Abstract:
A power over Ethernet (PoE) compliant device may be able to keep alive just enough of a management controller and/or target to respond to requests and tell a host (initiator) why it may be unable to respond to a data transfer request in a desired fashion due to a power failure. Thus only a small portion of an information handling system management capabilities need stay alive for reporting the operational condition of the overall information handling system during a power outage.

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to information handling systems and, more particularly, to using power-over Ethernet (PoE) compatible components for management and diagnoses of information handling systems, e.g., server/storage platforms. 
     BACKGROUND 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users are information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes, thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems, e.g., computer, personal computer workstation, portable computer, computer server, print server, network router, network hub, network switch, storage area network disk array, RAID disk system and telecommunications switch. 
     Information handling systems are becoming more and more important in both business and personal life. Important and critical information handling systems may be remote and/or unattended such as for example, but not limited to, servers and/or storage devices. Therefore, power failures/outages may be catastrophic to the operation of these servers and/or storage devices, leaving them unable to service user requests. For example, an iSCSI (Internet Small Computer System Interface) may be used to facilitate data transfers over intranets, e.g., local area networks (LANs) and/or to manage storage over long distances, e.g., wide area networks (WANs) and the Internet, thereby enabling location-independent data storage and retrieval. 
     The remote and/or unattended information handling systems that use, for example, iSCSI protocol would have no way of responding to a request if power was interrupted. Such a power interruption may leave iSCSI initiators and/or management applications with little information about the state of a target system except that it can no longer communicate with the initiator. Presently, information handling system servers and/or storage devices may use “flea power” to keep appropriate controllers and/or communications devices, e.g., network interface card (NIC), operational during hibernate or sleep modes, however, if there is a complete loss of utility (AC mains) power, even the flea power may no longer be available to power critical controllers and/or communications devices. 
     Power failures/outages may be catastrophic to information handling systems, e.g., servers and/or storage devices, especially when remote from the user&#39;s location and/or unattended, by rendering them unable to service any user requests and/or maintain data integrity. Information handling systems may use supplemental power sources, e.g., battery back-up systems, to provide temporary for the management and storage controllers under power failure conditions. The battery back-up systems may have limited life and add to the space required for the information handling system. 
     There may be a number of interface cards that during normal operation may be in critical stages when a power outage happens. Battery back-up systems may not be reliable and the batteries may malfunction or indicate false failure reports. Information handling system critical interfaces continue to increase their power requirements and may stretch battery back-up systems to their mechanical and electrical limits. 
     SUMMARY 
     Power over Ethernet (PoE) compliant controllers and/or communication devices do not lose their ability to operate and/or communicate with other PoE devices even if the information handling system loses AC mains power and/or power from an uninterruptible power supply (UPS). For example, a PoE powered device (PD) compliant with IEEE 802.3af, incorporated by reference herein for all purposes, e.g., network interface controller (NIC), may be particularly useful in applications such as an iSCSI storage system and/or a remote access controller (RAC). 
     For example, an iSCSI interface may stay alive even though power as been lost to its main information handling system. This stay alive ability of the PoE compliant iSCSI device may enable an iSCSI target to provide information (respond to an iSCSI initiator request) as to why it cannot fully respond to an initiator data access and/or storage request. This response capability may enable the requesting iSCSI initiator to perform a graceful disconnect instead of just assuming a lost connection/communication. Another example in a remote access controller compliant system is remote control of the system may still be possible even if a catastrophic AC power failure has occurred at the remote access controller compliant system. Thus, an administrator may still be able to remotely check on the remote access controller compliant system even with the AC power off. 
     In addition, out of band management may remain functional even if there has been AC power failure. The may allow management applications to report more specific information then just a lost connection/communication. 
     For a general server, a PoE compliant NIC and NIC driver in a remote server may be setup to detect whether or not the server system shutdown gracefully and respond as such to management applications such as HP OPENVIEW (a registered trademark of Hewlett-Packard Company) or IT Assistant. The PoE compliant NIC may also be able to send an alert (e.g., not a poll but rather an interrupt event) to the management application that may then be acted upon by the management application, e.g., page a system administrator. 
     Using PoE compliant interface devices in the information handling systems may go along way in solving the inherent problems with battery back-up. However, power management of the PoE compliant devices takes on added importance as more PoE compliant devices are deployed with the information handling systems, e.g., NICs on local area networks (LAN), because it becomes more important to have some intelligent power management and distribution system that may optimally utilize the supplemental power source (e.g., PoE). An intelligent power management and distribution system may be able to manage multiple PoE compliant powered devices from a PoE source. When needed, diverting power from one PoE compliant device to another may more effectively utilize the limited PoE source. 
     In a multi-PoE compliant device environment, PoE power allocation may be managed by either: a) Dynamic Power Allocation—based on each PoE compliant device power utilization, the PoE Power Manager performs continuous power monitoring of the power consumption by each PoE compliant device; or b) Static Power Allocation—where each PoE compliant device requests arbitrary power (similar to an IEEE 802.3af request) or the PoE Power Manager allocates arbitrary power to each of the PoE compliant devices. 
     According to a specific example embodiment of this disclosure, an information handing system comprises a method for performing management and diagnoses of information handling systems having power over Ethernet (PoE) compliant devices, said method comprising the steps of communicating with a plurality of PoE compliant devices, each of the plurality of PoE compliant devices being coupled to a one of a plurality of information handling systems; and determining a status of at least one of the plurality of information handling systems with the PoE compliant devices when the at least one of the plurality of information handling systems loses main power. 
     According to another specific example embodiment of this disclosure, a system for performing management and diagnoses of information handling systems having power over Ethernet (PoE) compliant devices, said system comprising: a plurality of information handling systems, each of the plurality of information handling systems having a PoE compliant device, wherein each of the PoE compliant devices are communicating with other ones of the PoE compliant devices; and at least one of the plurality of information handling systems performing management and diagnoses of the other ones of the plurality of information handling systems when any of the other ones of the plurality of information handling systems loses main power. 
     According to another specific example embodiment of this disclosure, a system for performing management and diagnoses of information handling systems having power over Ethernet (PoE) compliant devices, said system comprising: a plurality of information handling systems, each of the plurality of information handling systems having a PoE compliant device, wherein each of the PoE compliant devices are communicating with other ones of the PoE compliant devices; and at least one of the plurality of information handling systems performing management and diagnoses of the other ones of the plurality of information handling systems when any of the other ones of the plurality of information handling systems looses main power. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present disclosure thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a schematic block diagram of an information handling system, according to specific example embodiments of the present disclosure; 
         FIG. 2  is a schematic network diagram of a plurality of information handling systems accessible with PoE compliant devices, according to a specific example embodiment of the present disclosure; 
         FIG. 3  is a flow diagram for power management of a plurality of PoE compliant devices, according to a specific example embodiment of the present disclosure; and 
         FIG. 4  is a schematic block diagram of a plurality of PoE compliant devices coupled to a PoE power manager, according to a specific example embodiment of the present disclosure. 
     
    
    
     While the present disclosure is susceptible to various modifications and alternative forms, specific example embodiments thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific example embodiments is not intended to limit the disclosure to the particular forms disclosed herein, but on the contrary, this disclosure is to cover all modifications and equivalents as defined by the appended claims. 
     DETAILED DESCRIPTION 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, 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, 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), hardware or software control logic, read only memory (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, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     Referring now to the drawings, the details of specific example embodiments of the present invention are schematically illustrated. Like elements in the drawings will be represented by like numbers, and similar elements will be represented by like numbers with a different lower case letter suffix. 
     Referring to  FIG. 1 , depicted is an information handling system having electronic components mounted on at least one printed circuit board (PCB) (motherboard) and communicating data and control signals therebetween over signal buses, according to a specific example embodiment of the present disclosure. In one example embodiment, the information handling system is a computer system. The information handling system, generally referenced by the numeral  100 , comprises a plurality of physical processors  110 , generally represented by processors  110   a - 110   n , coupled to a host bus(es)  120 . A north bridge  140 , which may also be referred to as a memory controller hub or a memory controller, is coupled to a main system memory  150 . The north bridge  140  is coupled to the plurality of processors  110  via the host bus(es)  120 . The north bridge  140  is generally considered an application specific chip set that provides connectivity to various buses, and integrates other system functions such as a memory interface. For example, an Intel® 820E and/or 815E chip set, available from the Intel Corporation of Santa Clara, Calif., provides at least a portion of the north bridge  140 . The chip set may also be packaged as an application specific integrated circuit (ASIC). The north bridge  140  typically includes functionality to couple the main system memory  150  to other devices within the information handling system  100 . Thus, memory controller functions such as main memory control functions typically reside in the north bridge  140 . In addition, the north bridge  140  provides bus control to handle transfers between the host bus  120  and a second bus(es), e.g., PCI bus  170 , AGP bus  171  coupled to a video graphics interface  172  which drives a video display  174 . A third bus(es)  168  may also comprise other industry standard buses or proprietary buses, e.g., ISA, SCSI, I 2 C, SPI, USB buses through a south bridge(s) (bus interface)  162 . A disk controller  160  and input/output interface(s)  164  may be coupled to the third bus(es)  168 . At least one input/output interface  164  may be a PoE compliant device, e.g., Ethernet network interface card (PoE NIC). 
     Referring to  FIG. 2 , depicted is a schematic network diagram of a plurality of information handling systems accessible with PoE devices, according to a specific example embodiment of the present disclosure. Shown coupled to a network cloud  204  are a client computer  202 , a first PoE switch  206  and a second PoE switch  208 . The client computer  202 , first PoE switch  206  and second PoE switch  208  may be coupled to the network cloud  204  through serial data portals, e.g., Ethernet portals  222 ,  226  and  228  respectively. The Ethernet portals  222 ,  226  and/or  228  may also include (not shown) telephone (DSL), cable, wireless, satellite, etc., interfaces, for example but not limited to, an intranet, extranet, Internet and the like. 
     The first PoE switch  206  and a second PoE switch  208  may be power over Ethernet (PoE) compliant with the IEEE 802.3af standard and may include power sources for powering other connected PoE compliant devices. Other connected PoE compliant devices may be, for example but not limited to, a network interface card (NIC), an Ethernet hub, an Ethernet router, an DSL modem, a cable modem, wireless, e.g., WIFI, etc. 
     The network attached storage (NAS)  210  may have a PoE-NIC, a server  212  may have a PoE NIC, and an iSCSI system  216  may have a plurality of PoE NICs. A storage array network (SAN)  214  may be coupled to the server  212  over, for example, Fibre Channel (FC)  242  (dual FC connections  242   a  and  242   b  are shown). The SAN  214  may communicate with the first PoE switch  206  and the second PoE switch  208  over Ethernet connections  234  and  235 , respectively (e.g., over out of band management channels). The iSCSI system  216  may communicate with the first PoE switch  206  and the second PoE switch  208  over Ethernet connections  246  and  247 , respectively. The NAS  210  may communicate with the first PoE switch  206  over Ethernet connection  230  and/or the second PoE switch  208  (not shown). The server  212  may communicate with the first PoE switch  206  over Ethernet connection  232  and/or the second PoE switch  208  (not shown). 
     A systems user and/or administrator my use, for example but is not limited to, the client computer  202  to check on the status of any or all of the NAS  210 , server  212 , SAN  214 , and/or iSCSI system  216  through the first PoE switch  206  and/or the second PoE switch. The status of any of the aforementioned devices may be obtained by using management applications such as, for example but not limited to, HP OpenView®, IT Assistant, NaviSphere®, etc. 
     If AC mains power should fail on any one or more of the NAS  210 , server  212 , SAN  214 , and/or iSCSI system  216  then limited management application communications is still possible through the associated PoE compliant NICs coupled to the first PoE switch  206  and/or the second PoE switch  208 . 
     Failover may be supported in the iSCSI system  216  since both associated NICs may be PoE compliant and management status thereby stays functional (e.g., stays alive). This stay alive ability of the PoE compliant NICs in the iSCSI system  216  may enable the iSCSI system  216  as a target to provide information (respond to an iSCSI initiator request) as to why it cannot fully respond to an initiator data access and/or storage request. This response capability may enable the requesting iSCSI initiator (e.g., client computer  202 ) to perform a graceful disconnect instead of just assuming a lost connection/communication with the target iSCSI system  216 . Disks of the iSCSI system  216  may not be operational if AC mains power is lost, but valid SCSI responses may still come from the target iSCSI system  216  via the associated PoE NICs. 
     The SAN  214  may have multiple management modules that may be routed to separate PoE compliant switches (e.g., first PoE switch  206  and/or second PoE switch  208 ) thereby keeping the out of band management operational in the event of an AC mains power failure even though the storage disks therein may not be operational. 
     Referring now to  FIG. 3 , depicted is a flow diagram for power management of a plurality of PoE compliant devices, according to a specific example embodiment of the present disclosure. Step  302  determines whether the information handling system is functioning normally. When the information handling system is not functioning normally, step  304  determines whether the non-normal functional occurrence may be due to a power loss. If a power loss is determined in step  304 , then step  306  determines whether the information handling system has at least one PoE compliant interface device. If at least one PoE compliant interface device is determined in step  304 , then the number of PoE enabled devices, e.g., ports, of the information handling system are determined in step  308 . Step  310  determines whether power to any of the PoE enabled devices may be dynamically allocated. If dynamic power allocation to a PoE enabled device cannot be made then in step  312  prioritization of power to the PoE device is made according to a static PoE distribution internal to the information handling system based upon a predefined user configuration. If power to a PoE device may be dynamically allocated then in step  314  the power manager may dynamically reallocated power to each such PoE device. The power manager may manage power based upon the following criteria: PoE device subcomponent prioritization, and/or power consumption/utilization. Step  316  indicates that management for the PoE device is active and step  318  may report an initial power failure to a remote information handling system management station. In step  320 , the information handling system continues to be monitored for incoming management queries and diagnostics of the system power condition until step  322  determines that full system power has been restored. 
     Referring now to  FIG. 4 , depicted is a schematic block diagram of a plurality of PoE compliant devices coupled to a PoE power manager, according to a specific example embodiment of the present disclosure. Multiple PoE sources, generally represented by the numeral  402 , may be for example but not limited to, network interface controllers (NICs) having a PoE compliant power source(s). The multiple PoE sources  402  may be coupled to a PoE power manager  404 , and the PoE power manager  404  may be coupled to a plurality of PoE powered devices, e.g., PoE devices  406 ,  408 ,  410  and  412 . The PoE devices  406 - 412  may be controlled over a bidirectional dynamic allocation bus  418 , or by sending a static allocation device request over bus  414  and a static allocation reply from the PoE power manager  404  over bus  416 . 
     While embodiments of this disclosure have been depicted, described, and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those ordinarily skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and are not exhaustive of the scope of the disclosure.