Patent ID: 12210776

DETAILED DESCRIPTION

For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes. For example, an information handling system may be a personal computer (e.g., desktop or laptop), tablet computer, mobile device (e.g., personal digital assistant (PDA) or smart phone), server (e.g., blade server or rack server), a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, touchscreen and/or a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.

In one embodiment, IHS100,FIG.1, includes a processor102, which is connected to a bus104. Bus104serves as a connection between processor102and other components of IHS100. An input device106is coupled to processor102to provide input to processor102. Examples of input devices may include keyboards, touchscreens, pointing devices such as mouses, trackballs, and trackpads, and/or a variety of other input devices known in the art. Programs and data are stored on a mass storage device108, which is coupled to processor102. Examples of mass storage devices may include hard discs, optical disks, magneto-optical discs, solid-state storage devices, and/or a variety of other mass storage devices known in the art. IHS100further includes a display110, which is coupled to processor102by a video controller112. A system memory114is coupled to processor102to provide the processor with fast storage to facilitate execution of computer programs by processor102. Examples of system memory may include random access memory (RAM) devices such as dynamic RAM (DRAM), synchronous DRAM (SDRAM), solid state memory devices, and/or a variety of other memory devices known in the art. In an embodiment, a chassis116houses some or all of the components of IHS100. It should be understood that other buses and intermediate circuits can be deployed between the components described above and processor102to facilitate interconnection between the components and the processor102.

Referring now toFIG.2, an embodiment of a computing device200is illustrated that may include the direct-attached storage device software RAID system of the present disclosure. In an embodiment, the computing device200may be provided by the IHS100discussed above with reference toFIG.1and/or may include some or all of the components of the IHS100, and in specific examples may be provided by a server device. However, while illustrated and discussed as being provided by a server device, one of skill in the art in possession of the present disclosure will recognize that the functionality of the computing device200discussed below may be provided by other devices that are configured to operate similarly as the computing device200discussed below. In the illustrated embodiment, the computing device200includes a chassis202that houses the components of the computing device200, only some of which are illustrated and described below.

For example, the chassis202may house a processing system (not illustrated, but which may include the processor102discussed above with reference toFIG.1such as a Central Processing Unit (CPU)) and a memory system (not illustrated, but which may include the memory114discussed above with reference toFIG.1such as Dynamic Random Access Memory (DRAM)) that is coupled to the processing system and that includes instructions that, when executed by the processing system, cause the processing system to provide an operating system engine204that is configured to provide an operating system and/or otherwise perform the functionality of the operating system engines, and/or computing devices discussed below. In the illustrated embodiment, the memory system may also include instructions that, when executed by the processing system, cause the processing system to provide a software RAID engine204athat is configured to perform the functionality of the software RAID engines, software RAID subsystems, and/or computing devices discussed below.

To provide a specific example, the software RAID engine204amay include a software RAID driver that is configured to utilize hardware resources in the computing device (e.g., the CPU, memory, etc.) in order to create and manage RAID infrastructure and/or perform any of a variety of RAID operations known in the art without the need for dedicated/specialized RAID hardware (e.g., a dedicated hardware RAID controller). However, while the software RAID engine204ais illustrated and described as being included in the operating system and/or otherwise being provided by the operating system engine204(i.e., being provided by the processing/memory system combination that also provides the operating system engine204), one of skill in the art in possession of the present disclosure will appreciate how the software RAID engine204amay be provided separately from the operating system/operating system engine204while remaining within the scope of the present disclosure as well.

In an embodiment, the software RAID driver in the software RAID engine204awill include a Small Computer System Interface (SCSI)-based driver, and one of skill in the art in possession of the present disclosure will appreciate how such a SCSI-compliant driver may be configured to be utilized with any PCIe devices/PCIe controller devices (e.g., Advanced Host Controller Interface (AHCI) controllers, SAS controllers, virtual PCIe controllers, NVMe controllers, etc.), thus allowing a computing device manufacturer to provide a single SCSI-based software RAID driver on a plurality of different computing device configurations of computing devices manufactured by the computing device manufacturer in order to enable the software RAID functionality described below in any of those computing devices using the PCIe devices/PCIe controller devices included in those computing devices. To provide a specific example, the software RAID driver in the software RAID engine204amay be implemented using the native model of the VMWARE®n ESXi hypervisor available from VMWARE® Inc. of Palo Alto, California, United States, although other software RAID driver configurations will fall within the scope of the present disclosure as well.

In the illustrated embodiment, the memory system may also include instructions that, when executed by the processing system, cause the processing system to provide a hypervisor engine204bthat is configured to create and provide the virtual machines described below using the hardware resources in the computing device200, and/or perform any of the other functionality of the hypervisor engines, hypervisor subsystems, and/or computing devices discussed below. For example, the hypervisor engine204bmay be configured to provide a VMWARE®n ESXi hypervisor available from VMWARE® Inc. of Palo Alto, California, United States, although other hypervisors are envisioned as falling within the scope of the present disclosure as well. As such, the hypervisor engine204bmay include a VMKernal that is available in the VMWARE®n ESXi hypervisor discussed above and that may provide any of the functionality of the hypervisor engine204bdescribed below. However, while the hypervisor engine204bis illustrated and described as being included in the operating system and/or otherwise being provided by the operating system engine204(i.e., being provided by the processing/memory system combination that also provides the operating system engine204), one of skill in the art in possession of the present disclosure will appreciate how the hypervisor engine204bmay be provided separately from the operating system/operating system engine204while remaining within the scope of the present disclosure as well.

In the illustrated embodiment, the chassis202also houses one or more controller devices206that are coupled to the software RAID engine204a(e.g., via a coupling between the controller device(s)206and the processing system that provides the software RAID engine204a). As discussed in the specific examples provided below, the controller device(s)206may be provided by Peripheral Component Interconnect express (PCIe) controller devices that may be included in and/or coupled to PCIe devices that are not provided by storage devices. For example, the PCIe controller device(s)206may be physical or virtual PCIe controller devices and may be included in Host Bus Adapter (HBA) devices, Advanced Host Controller Interface (AHCI) devices, and/or other PCIe devices that would be apparent to one of skill in the art in possession of the present disclosure. However, while illustrated and described as being provided by PCIe controller device(s), one of skill in the art in possession of the present disclosure will appreciate how the controller device(s)206may be provided by other types of controller devices while remaining within the scope of the present disclosure as well.

In the illustrated embodiment, the chassis202also houses one or more controller devices208athat are coupled to the software RAID engine204a(e.g., via a coupling between the controller device(s)208aand the processing system that provides the software RAID engine204a). As illustrated and discussed in the specific examples provided below, the controller device(s)208amay be provided by Peripheral Component Interconnect express (PCIe) storage controller devices that are coupled to one or more storage devices208bthat may be provided by any of Non-Volatile Memory express (NVMe) storage devices, Serial Attached Small Computer System Interface (SCSI) (SAS) storage device, Serial AT Attachment (SATA) storage devices, and/or other storage devices that would be apparent to one of skill in the art in possession of the present disclosure. For example, the PCIe storage controller device(s)208amay be provided by physical or virtual PCIe storage controller devices and may include PCIe storage controller devices configured as NVMe storage controllers, SAS storage controllers, SATA storage controllers, and/or other PCIe storage controller devices that would be apparent to one of skill in the art in possession of the present disclosure. However, while illustrated and described as being provided by PCIe controller device(s), one of skill in the art in possession of the present disclosure will appreciate how the controller device(s)208amay be provided by other types of controller devices while remaining within the scope of the present disclosure as well.

In the illustrated embodiment, the chassis202also houses one or more controller devices210athat are coupled to the software RAID engine204a(e.g., via a coupling between the controller device(s)208aand the processing system that provides the software RAID engine204a). As illustrated and discussed in the specific examples provided below, the controller device(s)210amay be provided by Peripheral Component Interconnect express (PCIe) controller devices that are included in one or more storage devices210that may be provided by any of Non-Volatile Memory express (NVMe) storage devices, Serial Attached Small Computer System Interface (SCSI) (SAS) storage device, Serial AT Attachment (SATA) storage devices, and/or other storage devices that would be apparent to one of skill in the art in possession of the present disclosure. For example, the PCIe storage controller device(s)210amay be provided by physical or virtual PCIe storage controller devices and may include PCIe storage controller devices configured as NVMe storage controllers. However, while illustrated and described as being provided by PCIe controller device(s), one of skill in the art in possession of the present disclosure will appreciate how the controller device(s)210amay be provided by other types of controller devices while remaining within the scope of the present disclosure as well.

However, while three different embodiments of controller devices206,208a, and210aare illustrated and described as being included in the computing device200(e.g., stand-alone controller device(s), storage-device-connected controller device(s), and storage-device-integrated controller device(s)), one of skill in the art in possession of the present disclosure will appreciate how one or more of the controller devices206,208a, and/or210amay be omitted from the computing device200while remaining within the scope of the present disclosure as well. Furthermore, while not explicitly illustrated, one of skill in the art in possession of the present disclosure will appreciate how any of the controller devices208aand/or210amay be coupled to and/or may control multiple storage devices208band/or210, respectively, while remaining within the scope of the present disclosure as well.

Further still, one of skill in the art in possession of the present disclosure will appreciate how storage devices may be coupled to the software RAID engine204avia multiple controller devices (e.g., when an NVMe storage device with an integrated controller device is connected via an external controller device to the software RAID engine204a). As such, while a specific computing device200has been illustrated and described, one of skill in the art in possession of the present disclosure will recognize that computing devices (or other devices operating according to the teachings of the present disclosure in a manner similar to that described below for the computing device200) may include a variety of components and/or component configurations for providing conventional computing device functionality, as well as the direct-attached storage device software RAID functionality discussed below, while remaining within the scope of the present disclosure as well.

For example, one of skill in the art in possession of the present disclosure will appreciate how the present disclosure describes the direct-attached storage device software RAID system of the present disclosure implemented to operate with hypervisor subsystem such as the VMWARE® ESXi hypervisor subsystem described above. However, the inventors of the present disclosure have also developed a direct-attached storage device software RAID system may be implemented with an operating system (i.e., rather than a hypervisor subsystem) in order to allow software RAIDs to be provided using any types of direct-attached storage devices and any types of CPUs in a computing device similarly as described below, and that direct-attached storage device software RAID system is described in U.S. patent application Ser. No. 18/228,006, filed Jul. 31, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Referring now toFIG.3, an embodiment of a method300for providing a software Redundant Array of Independent Disk (RAID) using direct-attached storage devices in a computing device is illustrated. As discussed below, the systems and methods of the present disclosure provide for the presentation by a software RAID subsystem to a hypervisor subsystem of a single, primary controller device as being connected to a logical storage device provided by a plurality of physical storage devices, with the software RAID subsystem receiving commands from the hypervisor subsystem that are directed to the primary controller device and that identify a logical storage subsystem that is included in the logical storage device, and transmitting those commands to a subset of the physical storage devices that provide that logical storage subsystem via respective controller device(s) that couple the software RAID subsystem to that subset of physical storage devices.

For example, the direct-attached storage device software RAID system of the present disclosure may include a chassis housing a software RAID subsystem coupled to physical storage devices, controller devices, and a hypervisor subsystem housed in the chassis. The software RAID subsystem uses the physical storage devices to provide a logical storage device to the hypervisor subsystem. The software RAID subsystem also presents a first controller device to the hypervisor subsystem as a primary controller device that is connected to the logical storage device. When the software RAID subsystem receives a command from the hypervisor subsystem directed to the primary controller device and identifying a logical storage subsystem in the logical storage device, it transmits the command to each of a subset of the physical storage devices that provide the logical storage subsystem in the logical storage device via a respective one of the controller devices that couples the software RAID subsystem to that physical storage device. As such, software RAIDs may be provided using any types of direct-attached storage devices and any types of CPUs in a computing device, as well as provide a variety of other benefits that would be apparent to one of skill in the art in possession of the present disclosure.

The method300begins at block302where a software RAID subsystem configures a logical storage device using physical storage devices. With reference toFIG.4, in an embodiment of block302, the software RAID engine204ain the computing device200may perform logical storage device configuration operations400that may include discovering each of the controller devices206,208a, and210aand, in response, discovering each of the storage devices208band/or210coupled thereto, and then configuring a logical storage device using those storage devices208band/or210. In a specific example, each of the storage device(s)208amay be coupled to a PCIe controller device that is provided by one of the controller device(s)208adiscovered at block302, and each of the storage device(s)210may include a PCIe controller device that is provided by one of the controller device(s)210adiscovered at block302, while PCIe controller device(s) that are provided by the controller device(s)206and that are not coupled to storage devices may be discovered at block302as well.

For example, in response to the powering on, reset, reboot, and/or other initialization of the computing device200, the computing device200may enter a pre-boot mode in which the software RAID engine204aperforms any of a variety of software RAID operations and/or other techniques that would be apparent to one of skill in the art in possession of the present disclosure in order to configure a RAID using the storage devices208aand210that allows the software RAID engine204ato present those storage devices208aand210as one or more logical storage devices. As will be appreciated by one of skill in the art in possession of the present disclosure, the RAID maybe configured using the storage devices208aand210with a variety of standard RAID levels such as a RAID0, RAID1, RAID2, RAID3, RAID4, RAID5, or RAID 6, as well as combinations of standard RAID levels (e.g., RAID 1+0, also known as RAID10), non-standard RAID levels, and/or any other RAID levels that would be apparent to one of skill in the art in possession of the present disclosure.

The method300then proceeds to block304where the software RAID subsystem allocates memory space for a direct-attached storage device software RAID system. In an embodiment, at block304, the software RAID engine204ain the computing device200may perform memory space allocation operations that may include allocating memory space for use by the direct-attached storage device software RAID system of the present disclosure. For example, the memory space allocation operations performed by the software RAID engine204amay include allocating a memory space or other portion of the memory system that is used to provide the operating system engine204(e.g., operating system kernel memory) for use by the software RAID engine204ato perform any of the direct-attached storage device software RAID operations or other functionality discussed below. As will be appreciated by one of skill in the art in possession of the present disclosure, the memory space or other portion of the memory system allocated for use by the direct-attached storage device software RAID system may be referred to a “heap memory” that may be dynamically allocated to the software RAID driver provided by the software RAID engine204a(e.g., unlike memory space allocated to stacks), and one of skill in the art in possession of the present disclosure will recognize how the heap memory may be utilized to perform any of the functionality described below.

In a specific example, the allocation of the heap memory to the software RAID engine204amay be performed during module initialization operations that are performed when an operating system provided by the operating system engine204is loaded and calls those module initialization operations, and the software RAID engine204amay allocate the heap memory based on a number of storage devices (e.g., a maximum number of storage devices) that the software RAID engine204ais configured to support. However, while a specific example of the allocation of memory space for use by the direct-attached storage device software RAID system of the present disclosure has been described, one of skill in the art in possession of the present disclosure will appreciate how memory space may be allocated for use by the direct-attached storage device software RAID system using a variety of techniques that will fall within the scope of the present disclosure as well.

The method300then proceeds to block306where the software RAID subsystem and the hypervisor subsystem register a controller device supported by the software RAID subsystem. With reference toFIG.5, in an embodiment of block306, the controller device registration operations may include the software RAID engine204ain the computing device200performing supported controller device identification operations500that may include identifying controller devices that are supported by the software RAID engine204ato the hypervisor engine204bin the computing device200. For example, any of the controller devices206,208a, and/or210adiscovered at block302as discussed above may be identified to the hypervisor engine204bas supported controller devices at block306. In a specific example, at block306, the software RAID engine204amay generate a Peripheral Component Interconnect (PCI) IDentification (PCIID) file that identifies the PCIe controller devices that are supported by the software RAID engine204a, and may load or otherwise transmit that PCIID file to the hypervisor engine204b. However, while a specific example of the identification of controller devices to the hypervisor engine204bthat are supported by the software RAID engine204ahas been described, one of skill in the art in possession of the present disclosure will appreciate how the software RAID engine204amay identify supported controller devices to the hypervisor engine204busing other techniques that will fall within the scope of the present disclosure as well.

With reference toFIG.6A, in an embodiment of block306, the controller device registration operations may also include the hypervisor engine204bin the computing device200performing controller device attachment request operations600that may include the hypervisor engine204bgenerating and transmitting a controller device attachment request for one of the controller devices that was identified as being supported by the software RAID engine204a. For example, a VMkernal in the VMWARE®n ESXi hypervisor described above that provides the hypervisor engine204bmay generate and transmit an “AttachDevice” ESXi call that provides the controller device attachment request and that one of skill in the art in possession of the present disclosure will recognize provides an instruction to the software RAID engine to initialize and discover one of the controller devices that was identified as being supported via a SCSI transport layer. However, while a specific example of a controller device attachment request has been described, one of skill in the art in possession of the present disclosure will appreciate how the hypervisor engine204bmay request the initialization and discovery of controller devices using other techniques that will fall within the scope of the present disclosure as well.

With reference toFIG.6B, in an embodiment of block306and in response to receiving the controller device attachment request from the hypervisor engine204b, the controller device registration operations may also include the software RAID engine204ain the computing device200performing initialization and discovery operations602that may include the software RAID engine204ainitializing and discovering, in the specific example provided inFIG.6B, the one of the controller device(s)206identified by the hypervisor engine204bin the controller device attachment request. As will be appreciated by one of skill in the art in possession of the present disclosure, the initialization and discovery operations602performed by the software RAID engine204amay include any of a variety of initialization operations and discovery operations that would be apparent to one of skill in the art in possession of the present disclosure, and may depend on the protocol supported by that controller device (e.g., a SAS protocol, a SATA protocol, an NVMe protocol, etc.).

In some embodiments, following the initialization and discovery of the first controller device during the first iteration of block306, the software RAID engine204ain the computing device200may perform timer registration operations that may include registering a timer with the hypervisor engine204b. As discussed below, some embodiments of the present disclosure may include the utilization of a timer to determine when the last controller device has been registered as part of the controller device registration operations performed across one or more iterations of block306of the method300, and thus that timer may be registered by the software RAID engine204awith the hypervisor engine204bat block306using any of a variety of timer registration techniques that would be apparent to one of skill in the art in possession of the present disclosure. However, the registration of the timer is described as occurring at a particular point in method300(e.g., following initialization and discovery of the first controller device during the first iteration of block306), one of skill in the art in possession of the present disclosure will appreciate how the timer may be registered at other points in the method300while remaining within the scope of the present disclosure as well. Furthermore, other embodiments of the method300may utilize other techniques to determine when the last controller device has been registered as part of the controller device registration operations across one or more iterations of block306of the method300, and thus the timer registration operations may be skipped in those embodiments.

With reference toFIG.6C, in an embodiment of block306and in response to initializing and discovering the one of the controller device(s)206in the specific example provided inFIG.6B, the controller device registration operations may also include the software RAID engine204ain the computing device200performing controller device attachment confirmation operations604that may include the software RAID engine204aconfirming the completion of the controller device attachment request that was received from the hypervisor engine204bfor the one of the controller device(s)206in the specific example provided inFIG.6B. For example, in response to the successful initialization and discovery of a connected controller device and its corresponding storage device(s), the software RAID engine204amay confirm the attachment request to the hypervisor engine204b. While not illustrated or discussed in detail, one of skill in the art in possession of the present disclosure will appreciate how the software RAID engine204amay identify to the hypervisor engine204bany failures of the initialization and discovery of any connected controller devices and its corresponding storage device(s) as well.

With reference toFIG.6D, in an embodiment of block306, the controller device registration operations may also include the hypervisor engine204bin the computing device200performing hypervisor registration request operations606that may include the hypervisor engine204bgenerating and transmitting a hypervisor registration request to register the one of the controller devices in the specific example provided inFIG.6Bwith the hypervisor engine204b. For example, a VMkernal in the VMWARE®n ESXi hypervisor described above that provides the hypervisor engine204bmay generate and transmit an “ScanDevice” ESXi call that provides the hypervisor registration request and that one of skill in the art in possession of the present disclosure will recognize provides an instruction to the software RAID engine to register the one of the controller devices in the specific example provided inFIG.6Bin the hypervisor engine204b. However, while a specific example of a hypervisor registration request has been described, one of skill in the art in possession of the present disclosure will appreciate how the hypervisor engine204bmay request the registration of controller devices in the hypervisor engine204busing other techniques that will fall within the scope of the present disclosure as well.

With reference toFIG.6E, in some embodiments of block306and in response to receiving the hypervisor registration request (e.g., the “ScanDevice” ESXi call), the controller device registration operations may also include the software RAID engine204ain the computing device200performing hypervisor registration operations608that may include the software RAID engine204aregistering the one of the controller device(s)206in the specific example provided inFIG.6Bin the hypervisor engine204busing any of a variety of hypervisor/controller device registration techniques that would be apparent to one of skill in the art in possession of the present disclosure. For example, in response to a “ScanDevice” ESXi call, the software RAID engine204amay register the controller device with the hypervisor engine204band retrieve a “handle” for use in performing subsequent communications with that controller device, and then enable Input/Output (I/O) commands for the controller device from the hypervisor engine204bonce that registration is completed. However, in other embodiments of block306and in response to receiving the hypervisor registration request (e.g., the “ScanDevice” ESXi call), the hypervisor registration operations may instead include the software RAID engine204ain the computing device200“holding”, delaying, and/or otherwise waiting to perform the hypervisor registration operations608that register the one of the controller device(s)206in the specific example provided inFIG.6Bin the hypervisor engine204b.

The method300then proceeds to decision block308where it is determined whether there is an additional controller device supported by the software RAID subsystem to register. In some embodiments of decision block308, following the registration of the one of the controller device(s)206in the specific example provided inFIG.6Bin the hypervisor engine204bat block306, the software RAID engine204ain the computing device200may perform timer activation operations in order to activate the timer discussed above that may have been registered with the hypervisor engine204bin some embodiments of the present disclosure. The software RAID engine204amay then monitor that timer at decision block308to determine whether another controller device attachment request (e.g., the “AttachDevice” ESXi call in the specific example provided above) for another of the controller devices206,208b, and/or210ais received from the hypervisor engine204bwithin a threshold time period. As will be appreciated by one of skill in the art in possession of the present disclosure, the software RAID engine204amay utilize any of a variety of threshold time periods that, after which, the software RAID engine204amay assume that no further controller device attachment requests will be received (i.e., that there are no further controller devices to be registered with the hypervisor engine204b).

However, while the use of a timer and threshold time period following registration of any particular controller device in order to determine whether there are any other controller devices to register at decision block308has been described, as discussed above other techniques for determining whether there are any other controller devices to register at decision block308will fall within the scope of the present disclosure as well. For example, other embodiments of the present disclosure may provide a software driver in the computing device200that is configured to identify a number of available controller devices in the computing device200, and then transmit that number of available controller devices to the software RAID engine204afor use in determining at decision block308whether the number of controller devices registered with the hypervisor engine204ahas reached that number of available controller devices. As such, the determination of whether there are any other controller devices to register in the hypervisor engine204bduring decision block308of the method300may be performed in a variety of manners while remaining within the scope of the present disclosure.

If, at decision block308, it is determined that there is an additional controller device supported by the software RAID subsystem to register, the method300returns to block306. As such, the method300may loop such that the software RAID engine204aand the hypervisor engine204bin the computing device200operate to register any additional controller device with the hypervisor engine204b. Thus, different iterations of block306and decision block308may cause the software RAID engine204aand the hypervisor engine204bto register each of the controller devices in the computing device200in the hypervisor engine204b. For example, for any remaining controller devices206,208a, and210a, the controller device attachment request operations600, initialization and discovery operations602, controller device attachment confirmation operations604, hypervisor registration request operations606, and hypervisor registration operations608described above for block306may be performed for that controller device, and block306may repeat until it is determined that there are no additional controller devices to register with the hypervisor engine204b.

If, at decision block308, it is determined that there are no additional controller devices supported by the software RAID subsystem to register, the method300proceeds to block310where the software RAID subsystem creates one or more logical storage subsystems in the logical storage device. In an embodiment, at block310and in response to determining that there are no additional controller devices to register with the hypervisor engine204b, the software RAID engine204ain the computing device200may perform logical storage subsystem creation operations that may include creating one or more logical storage subsystems in the logical storage device provided by the storage devices208band210. For example, with reference toFIG.7, in some embodiments the logical storage subsystem creation operations may include the software RAID engine204aperforming metadata retrieval operations700that may include retrieving metadata from the controller devices208aand210acoupled to each of the storage devices208band210that are being used to provide the logical storage device.

As will be appreciated by one of skill in the art in possession of the present disclosure, the metadata retrieved from the controller devices208aand210acoupled to each of the storage devices208band210may identify one or more logical storage subsystems (e.g., virtual disks, RAID volumes, RAID Logical Unit Numbers (LUNs), and/or logical storage subsystems known in the art) that will be provided by each of the storage devices208band210, as well as any other information that one of skill in the art in possession of the present disclosure would recognize as providing for the creation of the logical storage subsystems in the logical storage device. As such, at block310, the logical storage subsystem creation operations performed by the software RAID engine204amay include using the metadata retrieved from the controller devices208aand210acoupled to each of the storage devices208band210to “build”, generate, and/or otherwise create one or more logical storage subsystems (e.g., virtual disks, RAID volumes, RAID LUNs, and/or logical storage subsystems known in the art) in the logical storage device that is provided by the storage devices208band210. However, while a specific example of the creation of logical storage subsystem(s) in a logical storage device has been described, one of skill in the art in possession of the present disclosure will appreciate how the logical storage subsystems may be created in the logical storage device using a variety of techniques that will fall within the scope of the present disclosure as well.

The method300then proceeds to block312where the software RAID subsystem configures command communications with the hypervisor subsystem. With reference toFIG.8, in an embodiment of block312, the software RAID engine204ain the computing device200may perform command communication configuration operations800that may include identifying a primary controller device from the plurality of controller devices206,208a, and210a. For example, the controller device206,208a, or210aidentified as the primary controller device at block312may be a PCIe controller device that may have been designated by a computing device manufacturer to operate as the primary controller device based on that PCIe controller device being common to a variety of different configurations of computing devices provided by the computing device manufacturer (and thus being present in each of those computing devices/computing device configurations if needed to implement the direct-attached storage device software RAID system of the present disclosure). In another example, the controller device206,208a, or210aidentified as the primary controller device at block312may be a PCIe controller device that is not configured to be “hot removed” from the computing device200. However, while a few specific examples of controller devices that may be identified as primary controller devices have been described, one of skill in the art in possession of the present disclosure will appreciate how any of a variety of criteria may be used to designate the controller device that may be identified as the primary controller device at block312while remaining within the scope of the present disclosure as well.

In a specific example, at block312, the software RAID engine204ain the computing device200may perform command communication configuration operations that may also include identifying a number of SCSI queues in a SCSI layer of the hypervisor engine204bthat are used by the hypervisor engine204bto communicate with the software RAID engine204a, and one of skill in the art in possession of the present disclosure will appreciate how any Input/Output (I/O) commands generated by the hypervisor engine204b(e.g., the VMKernal discussed above) will be mapped to one of those SCSI queues. Furthermore, the SCSI queues may be mapped to SAS, SATA, and/or NVMe protocol queues in the software RAID engine204aso that I/O commands generated by the hypervisor engine204bmay be transmitted to the storage devices208band210. As will be appreciated by one of skill in the art in possession of the present disclosure, the allocation of SCSI queues is typically dependent on the number of processing cores available in the processing system that provides the hypervisor engine204b, and thus the software RAID engine204amay request the SCSI queues from the hypervisor engine204b(e.g., the VMKernal described herein) based on the SCSI queue requirements and the number of processor cores that are available. However, while a few examples of command communication configuration operations have been described, one of skill in the art in possession of the present disclosure will appreciate how a variety of configuration operations may be performed in order to enable the communication functionality described below while remaining within the scope of the present disclosure.

In embodiments in which the software RAID engine204ain the computing device200“holds”, delays, and/or otherwise waits to perform the hypervisor registration operations608that register the controller device in the hypervisor engine204bwhen receiving the hypervisor registration requests (e.g., “ScanDevice” ESXi calls) discussed above, following the command communication configuration operations at block312the software RAID engine204amay perform the hypervisor registration operations608in response to each of those hypervisor registration requests (e.g., the software RAID engine204amay enable I/O commands for each storage device corresponding to a respective “ScanDevice” ESXi call provided by the hypervisor engine204bfor that storage device). Following those hypervisor registration operations, or following the command configuration operations at block312in embodiments in which those hypervisor registration operations are performed upon receiving the hypervisor registration requests during block306, the direct-attached storage device software RAID system completes initialization such that the RAID volume provided by the logical storage device is configured for use, and one of skill in the art in possession of the present disclosure will appreciate how a full RAID volume or partial RAID volume may be configured via the method300as described above, and may be used for runtime data, during boot/initialization, and/or for other RAID volume uses that would be apparent to one of skill in the art in possession of the present disclosure.

The method300then proceeds to block314where the software RAID subsystem presents one of the controller devices to the hypervisor subsystem as a primary controller device that is connected to the logical storage device. With reference toFIG.9, in an embodiment of block314and following the completion of the initialization of the direct-attached storage device software RAID system, the software RAID engine204amay present, to a plurality of virtual machines900a,900b, and up to900cthat are provided by the hypervisor engine204bin the computing device200, a primary controller device902(which as discussed above is provided by one of the controller devices206,208a, or210a) as being connected to a RAID logical storage device904that includes a RAID datastore904a(e.g., which may be provided “on top” of RAID LUN(s)) and that is provided using a plurality of physical storage devices906a,906b, and up to906c(which may be any of the storage devices208aand210registered with the hypervisor engine204bas discussed above). As will be appreciated by one of skill in the art in possession of the present disclosure, the RAID datastore904amay be provided in the RAID logical storage device904when the hypervisor engine204bis provided by the VMWARE® ESXi hypervisor discussed above, and refers to a partition that has a Virtual Machine File System (VMFS) file system type and that is created using VMWARE® tools (or the VMWARE® ESXi hypervisor itself) on top of RAID volumes/LUNs that are exposed to the VMWARE® ESXi hypervisor.

To provide a specific example, one of the controller device(s)206that is not connected to a storage device may be presented to the hypervisor engine204bas being connected to the RAID logical storage device904, although one of skill in the art in possession of the present disclosure will appreciate how any one of the controller devices208aor210amay be presented to the hypervisor engine204bas being connected to the RAID logical storage device904while remaining within the scope of the present disclosure as well. As will be appreciated by one of skill in the art in possession of the present disclosure, any of the controller devices206,208a, and210athat are not presented to the hypervisor engine204bas being connected to the RAID logical storage device904may instead be presented to the hypervisor engine204bas secondary controller devices that are not connected to the RAID logical storage device904or any of the storage devices906a-906c(i.e., despite at least some of those controller devices being physically connected to those storage devices906a-906c).

As such, each of the logical storage subsystems (e.g., virtual disks, RAID volumes, RAID LUNs, and/or logical storage subsystems known in the art) provided by the RAID logical storage device904are exposed to the virtual machines900a-900cprovided by the hypervisor engine204b(e.g., the VMKernal discussed above) via the primary controller device902. Thus, using some of the specific examples discussed above, each of the logical storage subsystems (e.g., virtual disks, RAID volumes, RAID LUNs, and/or logical storage subsystems known in the art) provided by storage devices906a-906bmay be presented to a user of the operating system provided by the operating system engine204as SCSI storage devices or otherwise being provided by SCSI storage devices.

The method300then proceeds to block316where the software RAID subsystem receives a command from the hypervisor subsystem that is directed to a primary controller device and that identifies a logical storage subsystem. With reference toFIG.10, in an embodiment of block316, the virtual machine900aprovided by the hypervisor engine204bin the computing device200may perform command provisioning operations1000that include generating a command that identifies a logical storage subsystem provided by the RAID logical storage device904(e.g., via the RAID datastore904aas illustrated inFIG.10), and transmitting that command to the primary controller device902that is presented as being connected to the RAID logical storage device904, which one of skill in the art in possession of the present disclosure will appreciate will result that in that command being received by the software RAID engine204ain the computing device200.

In an embodiment, the command transmitted by the virtual machine900aprovided by the hypervisor engine204bto the software RAID engine204amay include I/O commands such as a read command, a write command, and/or any other RAID commands that would be apparent to one of skill in the art in possession of the present disclosure. Furthermore, while the virtual machine900ais illustrated and described as providing the command received by the software RAID engine204aat block316, one of skill in the art in possession of the present disclosure will appreciate how any of the virtual machines900b-900cmay provide commands in a similar manner while remaining within the scope of the present disclosure as well.

Using the specific example provided above in which the software RAID engine204ais provided by a SCSI-based driver, any commands received at block316by the software RAID engine204afrom the virtual machines900a-900cprovided by the hypervisor engine204bmay be SCSI commands. Furthermore, as discussed in some of the specific examples above, the any commands received at block316by the software RAID engine204afrom the virtual machines900a-900cmay be mapped to SCSI queues in the hypervisor engine204bthat are used to communicate with the software RAID engine204aprovided by the SCSI-based driver, and thus the software RAID engine206amay receive those commands via the accessing of those SCSI queues.

The method300then proceeds to block318where the software RAID subsystem transmits the command to a subset of physical storage devices that provide the logical storage subsystem via respective controller device(s) that couple the software RAID subsystem to that subset of physical storage devices. With continued reference toFIG.10, in an embodiment of block318, the software RAID engine204amay perform command transmission operations1000aand100bthat, in the specific example illustrated inFIG.10, includes transmitting the command received at block316to the storage device906aand the storage device906cvia their respective controller device(s) (e.g., any of the controller device(s)208aand210a) based on those storage devices906aand906cproviding the logical storage subsystem identified in the command received by the software RAID engine204afrom the virtual machine900a. As will be appreciated by one of skill in the art in possession of the present disclosure, the commands1000aand1000btransmitted to the storage devices906aand906cmay be provided by modified versions of the command1000received from the virtual machine900a(e.g., SCSI commands received from the virtual machine900amay be translated to a protocol supported by the controller device/storage device to which it is transmitted.

For example, in response to receiving the command from the virtual machine900aprovided by the hypervisor engine204bin the computing device200, the software RAID engine204ain the computing device200may determine which of the storage devices906a-90bcprovide the logical storage subsystem identified in that command (e.g., the storage devices906aand906cin this specific example). As discussed above, in some specific examples, SCSI queues in hypervisor engine204bmay be mapped to SAS, SATA, and/or NVMe protocol queues in the software RAID engine204a, and thus the software RAID engine204amay provide any commands received from the virtual machines900a-900cin the protocol queues associated with the protocol utilized by the storage devices that provide the logical storage subsystem to which those commands are directed. As such, the command received by the software RAID engine204afrom the virtual machine900amay be placed in a protocol queue associated with the protocol used by the storage device906a, as well as in a protocol queue associated with the protocol used by the storage device906c.

In embodiments in which the software RAID engine204ais provided by a SCSI-based driver and the commands received from the virtual machine900aare SCSI commands, in the event the storage devices906aand/or906care SAS storage devices or otherwise use the SAS protocol, SCSI commands may be placed in a SAS protocol queue in the software RAID engine204aand then transmitted to the storage devices906aand/or906cvia their respective controller device(s) (e.g., any of the controller device(s)208aand210a). However, in the event the storage devices906aand/or906care SATA storage devices or otherwise use the SATA protocol, SCSI commands may be placed in a SATA protocol queue in the software RAID engine204a, translated using a SCSI translation layer in the software RAID engine204a(e.g., a SCSI-to-Frame Information Structure (FIS) translation), and then transmitted to the storage devices906aand/or906cvia their respective controller device(s) (e.g., any of the controller device(s)208aand210a). Similarly, in the event the storage devices906aand/or906care NVMe storage devices or otherwise use the NVMe protocol, SCSI commands may be placed in an NVMe protocol queue in the software RAID engine204a, translated using a SCSI translation layer in the software RAID engine204a(e.g., a SCSI-to-NVMe translation), and then transmitted to the storage devices906aand/or906cvia their respective controller device(s) (e.g., any of the controller device(s)208aand210a).

However, while a few specific examples of the translation of commands received from the virtual machines900a-900cprovided by the hypervisor engine204bbefore providing them to the storage devices906a-906cvia their respective controller devices have been described, one of skill in the art in possession of the present disclosure will appreciate that other command translations may be performed while remaining within the scope of the present disclosure as well. For example, one of skill in the art in possession of the present disclosure will appreciate how a PCIe controller device connected to a SAS controller device will operate as a SAS controller that utilizes the SAS protocol, and thus no command translations may be needed in such situations. Similarly, a PCIe controller device connected to a SATA controller device will operate as a SATA controller that utilizes the SATA protocol, and thus SCSI-to-FIS translations may be needed in such situations.

The method300then returns to block316. As such, the method300may loop such that the software RAID engine204ain the computing device200receives commands from the virtual machines900a-900cprovided by the hypervisor engine204bin the computing device200transmits those commands to the storage devices906a-906cvia their respective controllers as long as the storage devices906a-906care being used to provide the RAID logical storage device904/RAID datastore904ato the virtual machines900a-900c. While not described in detail herein, in the event the storage devices906a-906cwill no longer be used to provide the RAID logical storage device904/RAID datastore904ato the virtual machines900a-900c, the software RAID engine204amay disconnect the controller device(s)206,208a, and210afrom the hypervisor engine204b(e.g., via DetachDriver ESXi calls), as well as perform any other operations that would be apparent to one of skill in the art in possession of the present disclosure.

Thus, systems and methods have been described that provide for the presentation by a SCSI-based software RAID driver to a hypervisor of a single, primary PCIe controller device as being connected to a RAID logical storage device provided by a plurality of SAS, SATA, and/or NVMe physical storage devices, with the SCSI-based software RAID driver receiving I/O commands from the hypervisor that are directed to the primary PCIe controller device and that identify a RAID logical storage subsystem that is included in the RAID logical storage device, and transmitting those commands to a subset of the SAS, SATA, and/or NVMe physical storage devices that provide that RAID logical storage subsystem via respective PCIe controller device(s) that couple the SCSI-based software RAID driver to that subset of SAS, SATA, and/or NVMe physical storage devices. As such, software RAID support in hypervisor subsystem like the VMWARE® ESXi hypervisor discussed above is enabled in direct-attached storage device configurations for any types of storage devices and any types of CPUs, thus allowing the creation of a RAID using any available storage devices in a variety of computing devices. As such, RAID systems may be configured from a larger variety of storage devices and using spanned PCIe controllers, addressing several issues with the conventional RAID systems discussed above.

Referring now toFIGS.11A and11B, an embodiment of a method1100for providing crash dumps in a software Redundant Array of Independent Disk (RAID) using direct-attached storage devices in a computing device is illustrated. As discussed below, the systems and methods of the present disclosure provide for the presentation by a software RAID subsystem to a hypervisor subsystem of a single, primary controller device as being connected to a logical storage device provided by a plurality of physical storage devices, with the software RAID subsystem receiving crash dump commands from the hypervisor subsystem that are directed to the primary controller device and that identify a crash dump logical storage subsystem that is included in the logical storage device, and transmitting a respective second crash dump command to each of a subset of the plurality of physical storage devices that provide the crash dump logical storage subsystem via a respective one of the plurality of controller devices that couples the software RAID subsystem to that physical storage device, confirming completion of the respective second crash dump commands and, in response, transmitting a crash dump confirmation to the hypervisor subsystem. As such, crash dump operations are enabled using any logical storage subsystems (e.g., RAID LUNs or other RAID volumes) in a logical storage device regardless of whether that logical storage subsystem is “spanned” (e.g., provided using physical storage devices connected to two or more controller devices) or “non-spanned” (e.g., provided using physical storage devices connected to the same controller device).

As will be appreciated by one of skill in the art in possession of the present disclosure, the method1100may be performed prior to, during, and/or following the method300discussed above, and thus any of the blocks of the method300may be performed prior to the performance of any of the blocks of the method1100in order to configure the software RAID engine204a, the hypervisor engine204b, the operating system204, the controller devices206,208a, and210a, and/or the storage devices208band210to perform any of the functionality described below. In a particular example, the software RAID subsystem204ain the computing device200may perform any of blocks302,304,306,308,310,312, and/or316of the method300prior to or during the performance of the method1100in order to configure the logical storage device using the storage devices208aand210, allocate memory space for the direct-attached storage device software RAID subsystem, register the controller devices208aand210awith the hypervisor engine204b, create logical storage subsystems in the logical storage device, configure command communications with the hypervisor engine204b, and/or present one of the controller devices206,208a, and210aas the primary controller device connected to the logical storage device, while remaining within the scope of the present disclosure as well.

The method1100begins at block1102where a software RAID subsystem configures memory space for the direct-attached storage device software RAID crash dump system of the present disclosure. As will be appreciated by one of, block1102of the method1100may be provided during a “normal” or “runtime” mode for the computing device200and prior to the system crash described below. In an embodiment, at block1102, the software RAID engine204ain the computing device200may perform memory space configuration operations that may include configuring memory space or another portion of the memory system that is used to provide the operating system engine204(e.g., operating system kernel memory) for use by the software RAID engine204ato perform any of the direct-attached storage device software RAID crash dump operations or other functionality discussed below. In a specific example, the memory space configuration operations performed by the software RAID engine204amay include configuring the “heap memory” discussed above that was dynamically allocated to the software RAID driver provided by the software RAID engine204aat block304of the method300for the crash dump operations described below. For example, one of skill in the art in possession of the present disclosure will appreciate how “crash dump” heap memory may be configured at block1102of the method1100that is separate from the heap memory that was allocated for the operations of the direct-attached storage device software RAID system at block304of the method300(e.g., each may be provided by different portions of operating system memory), and may be allocated a crash dump memory size that is sufficient to perform any crash dump operations that would be apparent to I in the art in possession of the present disclosure.

In some embodiments, the memory space configuration operations may include configuring the “heap memory” at block1102for crash dump operations by configuring the heap memory for Direct Memory Access (DMA) operations that I in the art in possession of the present disclosure will appreciate may allow hardware subsystems to access that portion of the heap memory independently from the processing system (e.g., a CPU) that provides the operating system engine204a. As discussed below, the configuration of the heap memory for DMA operations may be performed in embodiments in which the logical storage device provided by the software RAID engine204ausing the storage devices208band210includes a RAID level that requires the calculation of parity data, although I in the art in possession of the present disclosure will appreciate how other reasons and/or uses of DMA operations via the heap memory will fall within the scope of the present disclosure as well.

In an embodiment, the configuration of the memory space for the direct-attached storage device software RAID crash dump system at block1102may include storing, in that memory space, identifiers for any of the controller devices208aand/or210athat couple the software RAID engine204ato storage devices208band/or210that provide a crash dump logical storage subsystem in the logical storage device. As will be appreciated by I in the art in possession of the present disclosure, crash dump functionality may be enabled in the computing device200(e.g., by default by a manufacturer of the computing device200, by a user of the computing device200, etc.) by designating a “crash dump” logical storage subsystem in the logical storage device provided by the storage devices208band/or210(e.g., a minimum of two storage devices may be designated for any RAID logical storage subsystem including the crash dump logical storage subsystem), and that crash dump logical storage subsystem may be identified in the memory space for the direct-attached storage device software RAID crash dump system (e.g., the crash dump heap memory discussed above). To provide a specific example, crash dump functionality may be enabled via the hypervisor engine204b(e.g., the VMWARE® ESXi hypervisor discussed above) in the operating system engine204of the computing device200by default on the “boot drive partition number7” in the logical storage device provided by the storage devices208band/or210, but may be modified by a user such that it is provided on any other crash dump logical storage subsystem in the logical storage device while remaining within the scope of the present disclosure as well.

As such, identifiers may be stored in the memory space for the direct-attached storage device software RAID crash dump system (e.g., the crash dump heap memory discussed above) at block1102for any of the controller device(s)208athat are coupled to the storage devices208bthat provide a crash dump logical storage subsystem, and/or for any the controller device(s)210aincluded in the storage devices210that provide a crash dump logical storage subsystem. As will be appreciated by I in the art in possession of the present disclosure, the identifiers for the controller device(s)208aand/or210acoupled to the storage devices208band/or210that provide a crash dump logical storage subsystem may be utilized during the crash dump operations discussed below to ensure that the software RAID engine204acan access any secondary controller device(s) (e.g., controller devices other than the primary controller device) coupled to the storage devices208band/or210that provide a crash dump logical storage subsystem (e.g., while any identifier for the primary controller device may not be needed due to the software RAID engine204aalready having access to the primary controller device by default). Furthermore, while not described in detail, I in the art in possession of the present disclosure will appreciate how the memory space for the direct-attached storage device software RAID crash dump system may also be utilized during the crash dump operations discussed below to transmit communications (e.g., RAID internal I/O commands, etc.) between the software RAID engine204aand the controller devices208aand210aduring those crash dump operations, as well as to perform any other functionality that would be apparent to I in the art in possession of the present disclosure.

The method1100then proceeds to block1104where the software RAID registers crash dump commands with the hypervisor subsystem. As will be appreciated by one of, block1104of the method1100may be provided during the “normal” or “runtime” mode for the computing device200discussed above and prior to the system crash described below. With reference toFIG.12, in an embodiment of block1104, the software RAID engine204ain the computing device200may perform crash dump command registration operations1200that include registering any crash dump commands with the hypervisor engine204bin the computing device200that will be utilized during the crash dump operations discussed below. Continuing with the specific example above in which the hypervisor engine204bis provided by the VMWARE® ESXi hypervisor discussed above, at block1104the software RAID engine204amay register a “dumpCommand” ESXi call with the hypervisor engine204bthat is configured to provide a submission entry point for any Input/Output (I/O) crash dump commands that will be provided by the hypervisor engine204bto the software RAID engine204aduring crash dump operations, as well as register a “dumpPollHandler” ESXi call with the hypervisor engine204bthat is configured to provide for the polling of the completion of I/O crash dump commands by the hypervisor engine204bwith the software RAID engine204aduring crash dump operations.

As will be appreciated by one of skill in the art in possession of the present disclosure, the registration of crash dump commands like those discussed above during the normal or runtime mode for the computing device200configures the hypervisor engine204bin the computing device200to communicate with the software RAID engine204ain the computing device200in the event of a crash like the system crash described below. However, while specific examples of the registration of crash dump commands with the hypervisor subsystem has been described, one of skill in the art in possession of the present disclosure in the art in possession of the present disclosure will appreciate how the crash dump communications and/or other operations discussed below may be enabled in a variety of manners that will fall within the scope of the present disclosure as well.

The method1100then proceeds to block1106where a system crash occurs. As will be appreciated by one of skill in the art in possession of the present disclosure, the computing device200may experience a “crash”, system fault, unavailability, or other issue with the computing device200that can render the computing device200unavailable (e.g., while providing a “crash screen” on a display connected to the computing device200that is often referred to as “pink screen of death”). In response to such a system crash, the hypervisor engine204bmay be configured to initiate a crash dump and generate any of a variety of Operating System (OS)-level crash dump commands (e.g., any of the crash dump commands registered with the hypervisor engine204bat block1104as discussed above) that are configured to instruct performance of the crash dump described below. However, while a specific system crash and subsequent operations of the hypervisor engine204bhave been described, one of skill in the art in possession of the present disclosure will appreciate how any of a variety of crash dump scenarios will fall within the scope of the present disclosure as well.

The method1100then proceeds to block1107where the software RAID subsystem receives a first/OS-level crash dump command from the hypervisor subsystem. As discussed above, in response to the system crash occurring at block1106, the hypervisor engine204bin the computing device200may generate OS-level crash dump commands (also referred to as “first” crash dump commands), and thus at block1007the software RAID engine204ain the computing device200may receive the OS-level crash dump commands from the hypervisor engine204bin the computing device200.

The method1100may then proceed to block1108where the software RAID subsystem identifies a subset of physical storage devices that provide a crash dump logical storage subsystem identified in the OS-level crash dump command. With reference toFIG.13, in an embodiment of block1107and in response to the “crash”, system fault, unavailability, or other issue with the computing device200, the hypervisor engine204bin the computing device200may automatically generate crash dump information related to the system issue that initiated the crash dump (e.g., the processes, drivers, programs, applications, and/or other components running or otherwise operating at the time of the system issue, the Kernel-mode stack that “stopped” or otherwise became unavailable, etc.), and may then generate an OS-level crash dump command (e.g., including the “dumpCommand” ESXi call discussed above) that is includes that crash dump information, that is directed to the primary controller device, and that identifies the crash dump logical storage subsystem in the logical storage device.

As will be appreciated by one of skill in the art in possession of the present disclosure and as discussed in further detail below, in response to the system crash at block1106, the computing device200may exit the normal or runtime mode discussed above and enter a “crash dump” mode in which the OS-level crash dump commands are sent directly from the hypervisor engine204bto the software RAID engine204ausing crash dump command callbacks registered at block1104, with the software RAID engine204athen passing those OS-level crash dump commands to the storage devices as the second/RAID-level crash dump commands described below that depend on the RAID level implemented in the RAID provided by the storage devices208band210.

As such, the receipt of the OS-level crash dump command by the software RAID engine204afrom the hypervisor engine204bmay initiate crash dump operations by the software RAID engine204a, and in response the software RAID engine204amay prevent rebuild operations and/or recovery operations associated with the logical storage device provided by the storage devices208band210by, for example, ignoring rebuild I/O commands and/or recovery I/O commands that may be generated during the crash dump operations.

In an embodiment, at block1108and in response to receiving the OS-level crash dump command from the hypervisor engine204bin the computing device200, the software RAID engine204ain the computing device200may use the crash dump logical storage subsystem identified in that OS-level crash dump command to identify the storage devices that provide that crash dump logical storage subsystem and/or the controller devices that couples those storage devices to the software RAID engine204a. For example, during the normal or runtime mode of the computing device200(e.g., prior to the crash dump operations and/or receipt of the OS-level crash dump command), the software RAID engine204amay access the crash dump heap memory discussed above and determine which of the storage devices208band/or210are identified as providing the crash dump logical storage subsystem, and/or the controller devices208aand/or210athat couple those storage devices208band/or210to the software RAID engine204a. Subsequently, at block1108and in response to receiving the OS-level crash dump command at block1107, the software RAID engine204amay determine that those storage devices provide the crash dump logical storage subsystem that is identified in the OS-level crash dump command that was received at block1107, and/or may identify the controller devices that couple those storage devices to the software RAID engine204a.

As such, in embodiments in which the storage devices208band/or210that provide the crash dump logical storage subsystem are coupled to multiple controller devices208aand/or210a(i.e., the crash dump logical storage subsystem is “spanned” on multiple controller devices), each of those controller devices208aand/or210awill be identified at block1108. As discussed above, the software RAID engine204amay already have default access to the controller device that is presented to the hypervisor engine204bas the primary controller device connected to the logical storage device, while access to any secondary controller devices may be enabled via the identification of those secondary controller devices at block1108in the crash dump heap memory. For example, in response to identifying each of the controller devices that couple software RAID engine204ato the storage devices that provide the crash dump logical storage subsystem, the software RAID engine204amay determine whether any of those controller devices that are inaccessible (e.g., which may include any secondary controller devices that couple the software RAID engine204ato the storage devices that provide the crash dump logical storage subsystem) and, in response, may initialize those controller devices so that they become accessible to the software RAID engine204a. As such, in situations in which storage devices that provide the crash dump logical storage subsystem are coupled to the software RAID engine204avia secondary controller devices, the identification and initialization of those secondary controller devices at block1108will ensure that the software RAID engine204acan access those secondary controller devices for crash dump operations.

The method1100then proceeds to block1110where the software RAID subsystem transmits second/RAID-level crash dump commands to the subset of physical storage devices that provide the crash dump logical storage subsystem via one or more respective controller devices that couple the software RAID subsystem to that subset of physical storage devices. In an embodiment, at block1110, the software RAID engine204ain the computing device200may generate RAID-level crash dump commands (also referred to below as “second” crash dump commands) for each of the storage devices that were identified at block1108as providing the crash dump logical storage subsystem in the logical storage device. For example, for any particular OS-level crash dump command that was directed to the primary controller device by the hypervisor engine204bin the computing device200and that identified the crash dump logical storage subsystem, the software RAID engine204amay generate a respective RAID-level crash dump command for each of the storage devices that provide the crash dump logical storage subsystem (i.e., a plurality of separate RAID-level crash dump I/O commands may be generated based on a single OS-level crash dump I/O command received from the hypervisor engine204b).

In some embodiments, the RAID-level crash dump commands may split the OS-level crash dump commands depending on the RAID level implemented on the RAID provided by the storage devices208band210. To provide a specific example, the OS-level crash dump command may be provided by a SCSI-based crash dump command that is submitted via the dump command callback described above, and the RAID-level crash dump commands may be provided by sub-commands that are generated from the OS-level crash dump command based on the number of storage devices providing the crash dump logical storage subsystem, as well as translated to the specific protocol(s) of the storage devices208band210to which they will be transmitted if necessary.

With reference toFIG.14, in an embodiment of block1110, the software RAID engine204ain the computing device200may then perform crash dump command transmission operations1400that may include transmitting the RAID-level crash dump commands generated at block1110to each of the storage devices208band/or210that provide the crash dump logical storage subsystem via the controller devices208aand/or210athat couple those storage devices208band/or210to the software RAID engine204a. To provide a specific example, the RAID-level crash dump commands may be transmitted by the software RAID engine204ato the storage devices208band/or210that provide the crash dump logical storage subsystem by submitting those RAID-level crash dump commands into submission queues in the controller devices208aand/or210athat couple those storage devices208band/or210to the software RAID engine204a, although other techniques for providing the RAID-level crash dump commands to those storage devices are envisioned as falling within the scope of the present disclosure as well.

As will be appreciated by one of skill in the art in possession of the present disclosure, the transmission of the RAID-level crash dump commands to each of the storage devices208band/or210that provide the crash dump logical storage subsystem via the controller devices208aand/or210athat couple those storage devices208band/or210to the software RAID engine204awill result in the initiation of the performance of crash dump operations by those storage devices/controller devices, which one of skill in the art in possession of the present disclosure will recognize may include storing any of the crash dump information that was generated by the hypervisor engine204bin the computing device200and received in the OS-level crash dump command. Furthermore, in embodiments in which the logical storage device provides a RAID level that requires parity calculations, the crash dump operations may include the utilization of the portion of the heap memory reserved for DMA operations in order to perform those parity calculations.

The method1100then proceeds to block1112where the software RAID subsystem polls completion queues in the one or more respective controller devices that couple the software RAID subsystem to the subset of the physical storage devices that provides the crash dump logical storage subsystem. With reference toFIG.15A, in an embodiment of block1112, the hypervisor engine204bin the computing device200may perform crash dump status request operations1500that may include providing a crash dump status request to the software RAID engine204ain the computing device200. For example, following its provisioning of the OS-level crash dump command at block1106, the hypervisor engine204bmay generate a crash dump status request (e.g., including the “dumpPollHandler” ESXi call discussed above) that is directed to the primary controller device and that identifies the OS-level crash dump command. In an embodiment, the crash dump status requests may be sent directly from the hypervisor engine204bto the software RAID engine204ausing crash dump command callbacks registered at block1104, with the software RAID engine204athen passing those crash dump status requests to the storage devices.

Furthermore, as discussed in further detail below, the hypervisor engine204bmay submit the “dumpCommand” ESXi call discussed above followed by the “dumpPollHandler” ESXi call, and until it receives a crash dump command completion confirmation in response to the “dumpPollHandler” ESXi call, it will not submit the next “dumpCommand” ESXi call as part of the crash dump (e.g., because its single threaded). Furthermore, the software RAID engine204awill respond directly to the hypervisor engine204bafter receiving the “dumpPollHandler” ESXi call with a confirmation if the “dumpCommand” ESXi call has been completed, and if multiple storage devices provide the crash dump logical storage subsystem, the software RAID engine204awill wait until each RAID-level crash dump sub-command provided to those storage devices has been completed before sending that confirmation to the hypervisor engine204b.

With reference toFIG.15B, in an embodiment and in response to receiving the crash dump status request from the hypervisor engine204bin the computing device200, the software RAID engine204ain the computing device200may perform completion queue polling operations1502that may include polling completion queues in each of the controller devices208aand/or210athat couple the software RAID engine204ato the storage devices208aand/or210that provide the crash dump logical storage subsystem, and determining whether the RAID-level crash dump command submitted to that storage device/controller device has been completed. However, while the polling of completion queues has been described as being performed to determine whether RAID-level crash dump commands provided to storage devices that provide the logical storage subsystem have been completed, other techniques for determining whether RAID-level crash dump commands provided to storage devices that provide the logical storage subsystem have been completed (e.g., storage devices/controller devices issuing crash dump interrupts to the software RAID engine204A) are envisioned as falling within the scope of the present disclosure as well.

The method1100then proceeds to decision block1114where it is determined whether the RAID-level crash dump commands have been completed. In an embodiment, at decision block1114and based on the completion queue polling operations1502performed at block1112, the software RAID engine204ain the computing device200may determine whether the RAID-level crash dump commands provided to storage devices that provide the crash dump logical storage subsystem have been completed. As discussed below, decision block1114may be performed to ensure that the RAID-level crash dump command provided to each storage device that provides the crash dump logical storage subsystem is indicated as having been completed in the completion queue of the controller device that couples that storage device to the software RAID engine204aprior to confirming the completion of the crash dump operations with the hypervisor engine204bin the computing device200. However, as discussed above, the storage devices that provide the crash dump logical storage subsystem (or their connected controller devices) may instead utilize crash dump interrupts to report their completion of RAID-level crash dump commands to the software RAID engine204awhile remaining within the scope of the present disclosure as well.

If, at decision block1114, it is determined that the RAID-level crash dump commands have not been completed, the method1100returns to block1112. As such, the method1100may loop such that the software RAID engine204ain the computing device200continues to poll the completion queues in the controller devices208aand/or210athat couple the software RAID engine204ato the storage devices208band/or210that provide the crash dump logical storage subsystem until it determines that each of the RAID-level crash dump commands that were provided to those storage devices/controller devices have been completed.

If, at decision block1114, it is determined that the RAID-level crash dump commands have been completed, the method1100proceeds to block1116where the software RAID subsystem transmits a crash dump confirmation to the hypervisor subsystem. With reference toFIG.15C, in an embodiment of block1116and in response to determining that each of the RAID-level crash dump commands that were provided to the storage devices208band/or210that provide the crash dump logical storage subsystem have been completed, the software RAID engine204ain the computing device200may perform crash dump confirmation transmission operations1504that may include transmitting a crash dump confirmation (e.g., a confirmation for the “dumpPollHandler” ESXi call discussed above) to the hypervisor engine204bin the computing device200that indicates that the OS-level crash dump command provided by the hypervisor engine204bat block1107has been completed.

The method1100then proceeds to decision block1118where the method1100proceeds depending on whether the crash dump has been completed. As will be appreciated by one of skill in the art in possession of the present disclosure, a crash dump may involve the hypervisor engine204bin the computing device200issuing a plurality of the OS-level crash dump commands described above. As such, in the event the crash dump has not been completed at decision block1118, the method1100may return to block1107. As such, the method1100may loop such that any OS-level crash dump command received by the software RAID engine204ain the computing device200from the hypervisor engine204bin the computing device200at block1107is provided to the storage devices that provide the crash dump logical storage subsystem using the RAID-level crash dump commands described above, with the completion of that RAID-level crash dump command by each of those storage devices confirmed so that a crash dump confirmation may then be provided by the hypervisor engine204bfor that OS-level crash dump command. Furthermore, when the crash dump is completed at decision block1118, the method1100may proceed to block1120where the computing device restarts.

Thus, systems and methods have been described that provide for the presentation by a software RAID subsystem to a hypervisor subsystem of a single, primary controller device as being connected to a logical storage device provided by a plurality of physical storage devices, with the software RAID subsystem receiving crash dump commands from the hypervisor subsystem that are directed to the primary controller device and that identify a crash dump logical storage subsystem that is included in the logical storage device, and transmitting a respective second crash dump command to each of a subset of the plurality of physical storage devices that provide the crash dump logical storage subsystem via a respective one of the plurality of controller devices that couples the software RAID subsystem to that physical storage device, confirming completion of the respective second crash dump commands and, in response, transmitting a crash dump confirmation to the hypervisor subsystem. As such, crash dump operations are enabled using any logical storage subsystems (e.g., RAID LUNs or other RAID volumes) in a logical storage device regardless of whether that logical storage subsystem is “spanned” (e.g., provided using physical storage devices connected to two or more controller devices) or “non-spanned” (e.g., provided using physical storage devices connected to the same controller device)

Although illustrative embodiments have been shown and described, a wide range of modification, change and substitution is contemplated in the foregoing disclosure and in some instances, some features of the embodiments may be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the embodiments disclosed herein.