Patent Publication Number: US-2020278946-A1

Title: Non-disruptive repair of enclosure controller components

Description:
BACKGROUND 
     Field of the Invention 
     This invention relates to systems and methods for non-disruptively repairing enclosure controller components. 
     Background of the Invention 
     Electronics enclosures typically include various control functions to manage and monitor parameters such as fan speed, bulk power supply, power boundaries, temperature, and the like. Often, these control functions are implemented with two controllers to provide redundant operation as well as provide the ability to repair or replace a controller (often embodied as a hardware expansion card) while maintaining operation of the enclosure. For cost reasons, a single controller may be used in some implementation or multiple controllers may be mounted on the same hardware expansion card. In such implementations, it may be difficult to maintain operation of the enclosure when a controller card is removed and/or repaired. 
     Furthermore, a controller card when installed and booted may reset power boundaries, fan speeds, environmental controls, and the overall enclosure control state. This may change the operating state of the enclosure. In implementations where redundant controllers on separate cards are used, the controller card under repair may be prevented from affecting the system until enabled by a higher level system function or the partner controller card. The enclosure controllers are therefore either not redundant or not present for extended periods of time during repair or replacement. Reboot of a controller card may, in some implementations, cause the enclosure power to default to an on state or cause the enclosure to shut off. Where a single controller is used, removing the controller card may, in certain implementations, cause the enclosure to shut off. 
     In view of the foregoing, what are needed are systems and methods to, when an enclosure controller card is repaired and/or replaced, enable the enclosure to maintain a current operating state. Ideally, such systems and methods will prevent automatic shut offs or other state changes when a controller card reboots. 
     SUMMARY 
     The invention has been developed in response to the present state of the art and, in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available systems and methods. Accordingly, embodiments of the invention have been developed to maintain a current operating state of an enclosure when a controller card of the enclosure is repaired and/or replaced. The features and advantages of the invention will become more fully apparent from the following description and appended claims, or may be learned by practice of the invention as set forth hereinafter. 
     Consistent with the foregoing, a method is disclosed for maintaining a current operating state of an enclosure when a controller card of the enclosure is repaired and/or replaced. In one embodiment, such a method maintains, within a controller card of an enclosure, operating parameters used to establish an operating state of the enclosure. The method further offloads, from the controller card while the controller card is installed in the enclosure, the operating parameters to a location external to the controller card. Upon removal of the controller card from the enclosure, the method maintains the operating state of the enclosure using the operating parameters stored in the external location. Upon reinstalling the controller card in the enclosure, the method may optionally retrieve the operating parameters from the external location and initialize the controller card with the operating parameters. 
     A corresponding system and computer program product are also disclosed and claimed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which: 
         FIG. 1  is a high-level block diagram showing one example of a network environment in which systems and methods in accordance with the invention may be implemented; 
         FIG. 2  is a high-level block diagram showing one embodiment of a storage system for use in the network environment of  FIG. 1 ; 
         FIG. 3  is a high-level block diagram showing components of a storage system such as that illustrated in  FIG. 2  contained within a rack; 
         FIG. 4  is a high-level block diagram showing various control components within an enclosure; 
         FIG. 5  is a high-level block diagram showing the offloading of controller card operating parameters to external components; 
         FIG. 6  is a high-level block diagram showing the maintaining of an operating state of the enclosure using the operating parameters stored in the external components; and 
         FIG. 7  is a high-level block diagram showing the retrieving of operating parameters from the external components and initializing the controller card with the operating parameters. 
     
    
    
     DETAILED DESCRIPTION 
     It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. 
     The present invention may be embodied as a system, method, and/or computer program product. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium may be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage system, a magnetic storage system, an optical storage system, an electromagnetic storage system, a semiconductor storage system, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage system via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++ or the like, and conventional procedural programming languages, such as the “C” programming language or similar programming languages. 
     The computer readable program instructions may execute entirely on a user&#39;s computer, partly on a user&#39;s computer, as a stand-alone software package, partly on a user&#39;s computer and partly on a remote computer, or entirely on a remote computer or server. In the latter scenario, a remote computer may be connected to a user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention may be described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, may be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus, or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     Referring to  FIG. 1 , one example of a network environment  100  is illustrated. The network environment  100  is presented to show one example of an environment where systems and methods in accordance with the invention may be implemented. The network environment  100  is presented by way of example and not limitation. Indeed, the systems and methods disclosed herein may be applicable to a wide variety of different network environments in addition to the network environment  100  shown. 
     As shown, the network environment  100  includes one or more computers  102 ,  106  interconnected by a network  104 . The network  104  may include, for example, a local-area-network (LAN)  104 , a wide-area-network (WAN)  104 , the Internet  104 , an intranet  104 , or the like. In certain embodiments, the computers  102 ,  106  may include both client computers  102  and server computers  106  (also referred to herein as “hosts”  106  or “host systems”  106 ). In general, the client computers  102  initiate communication sessions, whereas the server computers  106  wait for and respond to requests from the client computers  102 . In certain embodiments, the computers  102  and/or servers  106  may connect to one or more internal or external direct-attached storage systems  112  (e.g., arrays of hard-storage drives, solid-state drives, tape drives, etc.). These computers  102 ,  106  and direct-attached storage systems  112  may communicate using protocols such as ATA, SATA, SCSI, SAS, Fibre Channel, or the like. 
     The network environment  100  may, in certain embodiments, include a storage network  108  behind the servers  106 , such as a storage-area-network (SAN)  108  or a LAN  108  (e.g., when using network-attached storage). This network  108  may connect the servers  106  to one or more storage systems, such as arrays  110  of hard-disk drives or solid-state drives, tape libraries  114 , individual hard-disk drives  116  or solid-state drives  116 , tape drives  118 , CD-ROM libraries, or the like. To access a storage system  110 ,  114 ,  116 ,  118 , a host system  106  may communicate over physical connections from one or more ports on the host  106  to one or more ports on the storage system  110 ,  114 ,  116 ,  118 . A connection may be through a switch, fabric, direct connection, or the like. In certain embodiments, the servers  106  and storage systems  110 ,  114 ,  116 ,  118  may communicate using a networking standard or protocol such as Fibre Channel (FC) or iSCSI. 
     Referring to  FIG. 2 , one example of a storage system  110  containing an array of hard-disk drives  204  and/or solid-state drives  204  is illustrated. As shown, the storage system  110  includes a storage controller  200 , one or more switches  202 , and one or more storage drives  204 , such as hard-disk drives  204  and/or solid-state drives  204  (e.g., flash-memory-based drives  204 ). The storage controller  200  may enable one or more hosts  106  (e.g., open system and/or mainframe servers  106  running operating systems such z/OS, zVM, or the like) to access data in the one or more storage drives  204 . 
     In selected embodiments, the storage controller  200  includes one or more servers  206 . The storage controller  200  may also include host adapters  208  and device adapters  210  to connect the storage controller  200  to host devices  106  and storage drives  204 , respectively. Multiple servers  206   a ,  206   b  may provide redundancy to ensure that data is always available to connected hosts  106 . Thus, when one server  206   a  fails, the other server  206   b  may pick up the I/O load of the failed server  206   a  to ensure that I/O is able to continue between the hosts  106  and the storage drives  204 . This process may be referred to as a “failover.” 
     In selected embodiments, each server  206  may include one or more processors  212  and memory  214 . The memory  214  may include volatile memory (e.g., RAM) as well as non-volatile memory (e.g., ROM, EPROM, EEPROM, hard disks, flash memory, etc.). The volatile and non-volatile memory may, in certain embodiments, store software modules that run on the processor(s)  212  and are used to access data in the storage drives  204 . The servers  206  may host at least one instance of these software modules. These software modules may manage all read and write requests to logical volumes in the storage drives  204 . 
     One example of a storage system  110  having an architecture similar to that illustrated in  FIG. 2  is the IBM DS8000™ enterprise storage system. The DS8000™ is a high-performance, high-capacity storage controller providing disk and solid-state storage that is designed to support continuous operations. Nevertheless, the techniques disclosed herein are not limited to the IBM DS8000™ enterprise storage system  110 , but may be implemented in any comparable or analogous storage system  110 , regardless of the manufacturer, product name, or components or component names associated with the system  110 . Any storage system that could benefit from one or more embodiments of the invention is deemed to fall within the scope of the invention. Thus, the IBM DS8000™ is presented only by way of example and not limitation. 
     Referring to  FIG. 3 , in certain embodiments, the components of a storage system  110  such as that illustrated in  FIG. 2  may be contained in various enclosures  300  mounted, for example, within a rack  302 . For example, the storage drives  204  may be contained within storage drive enclosures  300   a , the host adapters  208  and/or device adapters  210  may be contained within I/O bay enclosures  300   c , the servers  206   a ,  206   b  may be contained within server enclosures  300   e , and so forth. In the illustrated embodiment, the rack  302  may also include an enclosure  300   b  that contains a hardware management console (HMC), enclosures  300   f  that contain uninterruptible power supplies (UPSs), and an enclosure  300   d  that contains high performance flash memory. These enclosures  300  are simply provided by way of example and not limitation. Other types of enclosures  300  are possible and within the scope of the invention. 
     Enclosures  300  such as those shown in  FIG. 3  typically include various control functions to manage and monitor parameters such as fan speed, bulk power supply, power boundaries, temperature, and the like, within the enclosure  300 . Often, these control functions are implemented with two controllers to provide redundant operation as well as provide the ability to repair or replace a controller (often embodied as a hardware expansion card) while maintaining operation of the enclosure  300 . For cost reasons, a single controller may be used in some implementation or multiple controllers may be mounted on the same hardware expansion card. In such implementations, it may be difficult to maintain operation of the enclosure  300  when a controller card is removed and/or repaired. 
     Furthermore, a controller card when installed and booted may reset power boundaries, fan speeds, environmental controls, and the overall control state of the enclosure  300 . This may change the operating state of the enclosure  300 . In implementations where redundant controllers on separate cards are used, the controller card under repair may be prevented from affecting the system until enabled by a higher level system function or the partner controller card. The enclosure controllers are therefore either not redundant or not present for extended periods of time during a repair or replacement. Reboot of a controller card may, in some cases, cause the enclosure power to default to an on state or cause the enclosure  300  to shut off. Where a single controller is used, removing the controller card may, in certain implementations, cause the enclosure  300  to shut off. Thus, systems and methods are needed to, when an enclosure controller card is repaired and/or replaced, enable the enclosure  300  to maintain a current operating state. Ideally, such systems and methods will prevent automatic shut offs or other state changes when a controller card reboots. 
       FIG. 4  is a high-level block diagram showing various control components that may be included within an enclosure  300 . As shown, in certain embodiments, an enclosure  300  may include a controller card  400  that manages and monitors operating parameters such as fan speed, bulk power supply, power boundaries, temperature, and the like. The controller card  400  may periodically set environment controls to appropriate values as determined from a desired system state and/or a current environment. The controller card  400  may, in certain embodiments, query sensors  404  and power states to identify fault conditions within an enclosure  300  and report or respond to these conditions. In certain embodiments, buffers such as I2C expanders  406 ,  408  may be used to set and hold control bits that establish an operating state of the enclosure  300 . In certain cases, fan control may require a constant modulated pulse width cycle to set the speed of the fan  410 . Stopping the modulated pulse may, in certain cases, cause the fan  410  to either go to a maximum or minimum speed. Removing control may, in certain cases, cause the fan  410  to go to a high or low speed. 
     In the illustrated embodiment, the controller card  400  is coupled to an interconnect planar  402  that contains various components  406 ,  408  (e.g., chips  404 ,  406 ,  408 ) connected to a bus  420 , such as an I2C bus  420 . These components  404 ,  406 ,  408  may include, for example, pulse width modulation (PWM) controllers  406  for controlling replaceable fans  410  of the enclosure  300 , I2C expanders  408  for controlling power supplies  412  of the enclosure  300 , or the like. In certain embodiments, the bus  420  may also communicate with various on-card power controllers  416  located on slave logic cards  414  connected to the interconnect planar  402 . The on-card power controllers  416  may turn the slave logic cards  414  on or off based on signals that are received from the controller card  400  through the bus  420 . 
     Referring to  FIG. 5 , in certain embodiments, the controller card  400  establishes and maintains various operating parameters  500  that control an operating state (e.g., fan speed, power supply settings, environmental settings, etc.) of the enclosure  300 . In certain embodiments in accordance with the invention, the operating parameters  500  may be offloaded from the controller card  400  to various components  406 ,  408 ,  416  external to the controller card  400 , such as components  406 ,  408  on the interconnect planar  402 , or logic cards  414  connected to the interconnect planar  402 . As the operating parameters  500  change in response to changing environmental conditions and/or sensor data associated with the enclosure  300 , the controller card  400  may update the operating parameters  500  within the external components  406 ,  408 ,  416  to reflect the updated operating parameters  500  on the controller card  400 . 
     Referring to  FIG. 6 , when the controller card  400  is decoupled  600  from the interconnect planar  402 , such as when the controller card  400  is repaired or replaced, systems and methods in accordance with the invention may utilize the operating parameters  500  stored in the components  406 ,  408 ,  416  to maintain a current operating state of the enclosure  300 . More specifically, the components  406 ,  408 ,  416  may use the internally stored operating parameters  500  to maintain an operating state of the enclosure  300  that existed at the time the controller card  400  was decoupled  600  (e.g., removed) from the enclosure  300 . This will enable fans speeds, power supply states, environmental settings, and the like to continue uninterrupted within the enclosure  300  even after removal of the controller card  400 . 
     Referring to  FIG. 7 , when a controller card  400  is recoupled to the interconnect planar  402 , the controller card  400  may, in certain cases, be configured to retrieve the operating parameters  500  from the components  406 ,  408 ,  416  and initialize itself with these operating parameters  500 . This will allow the newly installed controller card  400  to maintain the current operating state of the enclosure  300 . The newly installed controller card  400  may then begin to control and adjust the operating parameters  500  and associated operating state in accordance with changing environmental conditions and/or sensor input data as the controller card  400  did prior to its removal. In the event operating parameters  500  are not available, such as if the enclosure  300  is not active or is shut off, the newly installed controller card  400  may initialize itself with a set of default or standby operating parameters  500  that may then be adjusted in accordance with changing environmental conditions and/or sensor input data. In this way, the operating state of the enclosure  300  may be maintained with little if any interruption. After a controller card  400  is reinstalled, the operating parameters  500  may once again be continually updated on the components  406 ,  408 ,  416  in the event the controller card  400  needs to be removed or repaired again at some point in the future. 
     The flowcharts and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer-usable media according to various embodiments of the present invention. In this regard, each block in the flowcharts or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, may be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.