Abstract: A slice manager module, in the operating system of a storage server, manages the virtual slicing of a mass storage device. The slice manager module receives a notification that a mass storage device has been added to an array of mass storage devices coupled to the storage system. The slice manager module reads header information in the mass storage device to determine a format of the mass storage device. If the mass storage device has not been previously sliced, the slice manager module virtually slices the mass storage device into a plurality of slices, where virtually slicing the mass storage device includes specifying an offset in the mass storage device where each of the plurality of slices is located.

Abstract: A system and method for logging and storing failure analysis information on disk drive so that the information is readily and reliably available to vendor customer service and other interested parties is provided. The information, in an illustrative embodiment, is stored on a nonvolatile (flash) random access memory (RAM), found generally in most types of disk drives for storage of updateable disk drive firmware. A known location of limited size is defined in the flash RAM, to form a scratchpad. This scratchpad is a blank area of known addresses, formed during the original firmware download onto the memory, and which is itself free of firmware code. This scratchpad is sufficient in size to write a series of failure codes in a non-erasable list as failures/errors (and user/administrator attempts to unfail the disk) are logged.

Abstract: A method for operating a computer data storage system is described. A recoverable error in a data storage device in recognized in response to receiving a command for a write operation. It is determined whether the data storage system is in a degraded state. The write operation encountering the recoverable error is reassigned to a space on a spare data storage device if the data storage system is not in a degraded state. The write operation is stored to reassign to a spare data storage device at a future time if the data storage system is in a degraded state.

Abstract: A method and system for injecting a deterministic fault into storage shelves in a storage subsystem. The method comprises injecting a known fault condition on demand into a hardware component in a storage shelf to cause a failure of the storage shelf. The hardware component incorporates a circuit that is configurable to select between a normal operating condition and a faulty condition of the hardware component. The method further comprises verifying that a reported failure is consistent with the known fault condition.

Abstract: A field-upgradeable database that is separable from system software contains information about mass storage devices that may be present in a storage array. When an uninitialized device is detected in the array, the field-upgradeable database is consulted to discover which non-standard functions the device supports, and one of the non-standard functions is activated. Software and systems using the field-upgradeable database in a storage server configuration are also described and claimed.

Abstract: A data storage system has a network adapter to receive an I/O request. A status signal is generated in response to the I/O request, the status signal indicating a failure of a storage media to which the I/O request was directed. An operating system determines, in response to the status signal, if the storage media is in a degraded mode. If the storage media is in a degraded mode, the operating system stores the I/O operation in a log for execution at a later date. If the storage media is not in a degraded mode, the operating system reassigns the I/O request to a spare storage media. The operating system places an appropriate entry of a faulty media onto a defect list that maps to a spares pool to aid reassignment of subsequent I/O requests.

Abstract: A method and an apparatus to aggressively detect media errors on storage devices with negligible performance impact have been disclosed. In one embodiment, the method includes computing a first data rate at or above which a scrub on a set of storage devices can be completed within a predetermined period of time, and running the scrub on the storage devices at a second data rate without interfering with the storage devices servicing client requests to access the storage devices, the second data rate being at or above the first data rate.

Abstract: A drive shelf includes an embedded switching hub (ESH) that monitors Fibre Channel Arbitrated Loop (FC-AL) traffic, including loop initialization requests (LIRs), coming from drives attached to the ESH. When a number of LIRs issued by a single drive within a certain amount of time exceeds a threshold, the drive is bypassed. One threshold (a “burst” threshold) measures the number of LIRs issued within a short period of time. If the number exceeds a threshold that would prevent other data from circulating through the loop, the drive is bypassed. A second threshold (a long-term threshold) measures the number of LIRs issued within a longer period of time. If the drive issues a number of LIRs at a slower rate than the burst threshold, but still above the long-term threshold, the drive is bypassed.

Abstract: A system and method for logging and storing failure analysis information on disk drive so that the information is readily and reliably available to vendor customer service and other interested parties is provided. The information, in an illustrative embodiment, is stored on a nonvolatile (flash) random access memory (RAM), found generally in most types of disk drives for storage of updateable disk drive firmware. A known location of limited size is defined in the flash RAM, to form a scratchpad. This scratchpad is a blank area of known addresses, formed during the original firmware download onto the memory, and which is itself free of firmware code. This scratchpad is sufficient in size to write a series of failure codes in a non-erasable list as failures/errors (and user/administrator attempts to unfail the disk) are logged.

Abstract: A system and method for reducing unrecoverable errors in a disk drive by undertaking an aggressive reassignment of slow-reading or currently recoverable-but-erroneous sectors to the spares pool is provided. A recovered error is treated by the system operating system as a fatal error and thereby the sectors involved are reassigned to the spares pool immediately. Reassignment is recommended by a reassignment utility at the disk interface level, which passes a status up to the RAID subsystem by which reassignment is performed. In order to prevent a double-disk panic, the RAID subsystem is instructed to ignore reassignment recommendations of this type (e.g. reassignment of recoverable errors) if the RAID group is currently operating in a degraded state. However, if the RAID group is undegraded, then immediate assignment of the sectors encountering the recoverable error is undertaken.

Abstract: A field-upgradeable database that is separable from system software contains information about mass storage devices that may be present in a storage array. When an uninitialized device is detected in the array, the field-upgradeable database is consulted to discover which non-standard functions the device supports, and one of the non-standard functions is activated. Software and systems using the field-upgradeable database in a storage server configuration are also described and claimed.

Abstract: A method and an apparatus to maintain storage devices in a storage system have been disclosed. In one embodiment, the method includes logically migrating a storage device out of a set of storage devices storing data in a storage system without physically decoupling the storage device from the storage system and performing a maintenance operation on the storage device without interrupting storage service provided by the storage system.

Abstract: A system and method for logging and storing failure analysis information on disk drive so that the information is readily and reliably available to vendor customer service and other interested parties is provided. The information, in an illustrative embodiment, is stored on a nonvolatile (flash) random access memory (RAM), found generally in most types of disk drives for storage of updateable disk drive firmware. A known location of limited size is defined in the flash RAM, to form a scratchpad. This scratchpad is a blank area of known addresses, formed during the original firmware download onto the memory, and which is itself free of firmware code. This scratchpad is sufficient in size to write a series of failure codes in a non-erasable list as failures/errors (and user/administrator attempts to unfail the disk) are logged.

Abstract: A method and an apparatus to aggressively detect media errors on storage devices with negligible performance impact have been disclosed. In one embodiment, the method includes computing a first data rate at or above which a scrub on a set of storage devices can be completed within a predetermined period of time, and running the scrub on the storage devices at a second data rate without interfering with the storage devices servicing client requests to access the storage devices, the second data rate being at or above the first data rate.

Abstract: A system and method for reducing unrecoverable errors in a disk drive by under-taking an aggressive reassignment of slow-reading or currently recoverable-but-erroneous sectors to the spares pool is provided. A recovered error is treated by the system operating system as a fatal error and thereby the sectors involved are reassigned to the spares pool immediately. Reassignment is recommended by a reassignment utility at the disk interface level, which passes a status up to the RAID subsystem by which reassignment is performed. In order to prevent a double-disk panic, the RAID subsystem is instructed to ignore reassignment recommendations of this type (e.g. reassignment of recoverable errors) if the RAID group is currently operating in a degraded state. However, if the RAID group is undegraded, then immediate assignment of the sectors encountering the recoverable error is undertaken.

Abstract: A system and method for the reliable firmware update of a disk connected to a fibre channel loop fabric allows the specified filers and other predetermined system devices connected to the fabric to be made aware of a firmware download to the target disk without need of a system broadcast message, and while avoiding an alert or error condition such as those encountered through an FC-AL reset request. The target disk returns a special downloading firmware reject code embedded in a low-level protocol that remains operative during a firmware download. This reject code is recognized by an accessing system device as indicating that the disk is currently downloading updated firmware. In this manner, having recognized the code, the system device holds any I/O operations with respect to the target disk for a given delay time. Thus, the system device does not misinterpret the unavailability of the disk as a failure, leading to an unwanted system-wide FC-AL reset state.