Abstract: A data storage system includes interface circuitry receiving data storage requests and sending corresponding responses to data storage clients, and data storage devices providing non-volatile storing and retrieval of client data in response to the data storage requests. Processing circuitry executes software-implemented datapath modules that realize datapath functions to process the data storage requests and responses, as well as service infrastructure modules to realize a service infrastructure to provide for regularized communications among the datapath modules, including Notify, Monitor, and StartIO communications.

Abstract: The techniques presented herein provide managing embedded and external key management systems in a data storage system. An embedded encryption key management system is selected. A first unique signature is generated using a time parameter and a randomly generated value. A backup copy of the lockbox is created, wherein access to the backup copy of the lockbox requires providing a minimum number of unique data storage system values. The encryption key management system is switched to external. A second unique signature is generated for use with the local lockbox, wherein the signature generated using a time parameter and a randomly generated value. The encryption key management system is switched back to embedded and a third unique signature is generated for use with the local lockbox, wherein the signature is generated using a time parameter and a randomly generated value.

Abstract: A method is used in managing data in a data storage system. A first set of flash drives in arranged into a redundant array of independent disks (RAID) group and a wear indicator for each of the flash drives in the first set of flash drives is determined. A second set of flash drives are configured, where the second set of flash drives are configured as spare flash drives and a wear metric is determined for each of the flash drives in the second set of flash drives. A first flash drive in the first set of flash drives that is to be replaced is identified. A spare flash drive from the second set of flash drives is selected, where the spare flash drive is selected based on a wear metric. A rebuild process is initiated where the first flash drive is replaced with the selected spare flash drive.

Abstract: Technique provides resiliency to RAID group including storage devices. Technique involves operating RAID group in normal state in which each storage device is initially online to perform write and read operations and configured to go offline in response to a media error count for that storage device reaching an end-of-life threshold and other storage devices in RAID group being healthy. Technique involves receiving a notification that a storage device of RAID group has encountered an error situation. Technique involves determining whether other storage devices of RAID group are healthy. Technique involves transitioning, in response to receiving notification and determining that other storage devices are healthy, RAID group from normal state to high resiliency degraded state in which the storage device is taken offline and the other storage devices are configured to remain online for facilitating the reconstruction of data associated with the storage device.

Abstract: A technique is directed to providing resiliency to a redundant array of independent disk (RAID) group which includes multiple storage devices. The technique involves operating the RAID group in a normal state in which each storage device is (i) initially online to perform write and read operations and (ii) configured to go offline in response to a respective media error count for that storage device reaching an initial take-offline threshold. The technique further involves receiving a notification that a storage device of the RAID group has encountered a particular error situation. The technique further involves transitioning, in response to the notification, the RAID group to a high resiliency state in which each storage device that is operable is (i) still online to perform write and read operations and (ii) configured to stay online even when the respective media error count for that storage device reaches the initial take-offline threshold.

Abstract: A method, a system and a computer program product for upgrading firmware is disclosed. In one embodiment data storage is managed in a data storage system comprising a first enclosure having a first storage processor and a first power supply. A firmware upgrade is saved in the first storage processor. The firmware upgrade in the first storage processor and firmware in the first power supply are compared. The firmware upgrade is downloaded to the first power supply in response to the comparison determining a difference between the firmware upgrade in the first storage processor and the firmware in the first power supply. The firmware is upgraded in the first power supply with the firmware upgrade.

Abstract: A method, system, and computer program product for use in upgrading disk drive firmware in a data storage environment, comprising selecting a first physical disk from a set of physical disks, the first physical disk having firmware; wherein the physical disks are mapped to a set of logical disks, wherein the mapping of the physical disks to the set of logical disks includes a RAID system, removing the first physical disk, wherein based on the RAID system, removal of the first physical disk is transparent to I/O to the set of logical disks, and upgrading the firmware of the first physical disk while allowing I/O access to the set of logical disks.

Abstract: Described are techniques for managing a data storage system. First energy information for each of one or more enclosures of the data storage system is determined. Second energy information for the data storage system based on information including the first energy information for the one or more enclosures is determined. It is determined whether any of the first energy information for each of the one or more enclosures and the second energy information for the data storage system are within a predetermined amount of one or more associated thresholds. If it is determined that any of the first energy information for each of the one or more enclosures and the second energy information for the data storage system are within a predetermined amount of one or more associated thresholds, one or more actions are taken prior to reaching the one or more associated thresholds.

Abstract: Hardware faults in data storage systems are diagnosed. User I/O errors are received. Disk drive port error counters, primary port error counters, and expansion port error counters are read. A user I/O error threshold is modified based on the error counter readings. Depending on the type of errors counted, the user I/O error threshold may be increased or decreased. Once a first quantity of user I/O errors exceeds the modified user I/O error threshold, a faulty component is identified.

Abstract: A method is used in managing loop interface instability. It is determined that a loop has excessive intermittent failures. It is determined, based on whether the intermittent failures are detectable on another loop, whether the cause of the excessive intermittent failures is within a specific category of components. A search procedure is executed that is directed to the specific category of components, to isolate the cause of the excessive intermittent failures.

Abstract: Loop interface failure is managed. A first device on a loop is identified as a potential cause of the loop interface failure. The loop is tested with the first device functionally removed from the loop. Depending on the results of the test, it is determined that the first device is not the cause of the loop interface failure and a second device on the loop is identified as the cause of the loop interface failure.

Abstract: A method for automatically diagnosing faults a data storage system. The system includes a plurality of enclosures each having: a primary port; an expansion port; a plurality of disk drives; and a link control card coupled to the primary port and to the expansion port and the plurality of disk drives. The link control card includes a cut through switch having: disk drive port error counters for counting at ports of the plurality of disk drives; a primary port error counter for counting cumulative errors at the primary port, and an expansion port error counter for counting cumulative errors at the expansion port. The primary ports and expansion ports are serially interconnected to the storage processor through a fiber channel loop. The method sequentially reads counters in each one of the enclosures to determine whether errors counted in any one of such counters exceeds a predetermined threshold over a predetermined period of time.

Abstract: Storage stability is managed. It is detected that a disk drive is requesting to be taken offline. The disk drive is begun to be treated as being in a probation state. If within an acceptable period of time the disk drive requests to be put back online, treatment of the disk drive as being in a probation state is stopped, and only any portions of the disk drive data that were the subject of write requests involving the disk drive while the disk drive was being treated as being in a probation state are rebuilt.

Abstract: System stability is managed. It is determined that a data storage system is responsive to an enclosure that is unstable. Based on the determination, the enclosure is temporarily prevented from being added to the data storage system.

Abstract: A system sets a disk access inhibitor flag whenever a disk drive is placed by the system in an inaccessible condition. The drive operates to set a bit therein when the drive has placed itself in a by-pass condition. During each polling event, the system determines: (1) whether the bit has been set; and (2) whether the disk access inhibitor flag has been set. If the bit has been set and such disk access inhibitor flag has been set, the system maintains the drive in the inaccessible condition; otherwise, the drive is accessible to the system. If, during a polling event, the bit has been set but that drive has not had a bit set during a relatively long period of time, the system maintains the drive accessible to the system unless the drive sets the bit during a subsequent predetermined wait period, after which the system sets the flagdisk access inhibitor flag and places the drive in the inaccessible condition.

Abstract: Storage stability is managed. It is detected that a disk drive is requesting to be taken offline. The disk drive is begun to be treated as being in a probation state. If within an acceptable period of time the disk drive requests to be put back online, treatment of the disk drive as being in a probation state is stopped, and only any portions of the disk drive data that were the subject of write requests involving the disk drive while the disk drive was being treated as being in a probation state are rebuilt.

Abstract: System stability is managed. It is determined that a data storage system is responsive to an enclosure that is unstable. Based on the determination, the enclosure is temporarily prevented from being added to the data storage system.