2958 results about "RAID" patented technology

Storage virtualization systems and methods that allow customers to manage storage as a utility rather than as islands of storage which are independent of each other. A demand mapped virtual disk image of up to an arbitrarily large size is presented to a host system. The virtualization system allocates physical storage from a storage pool dynamically in response to host I / O requests, e.g., SCSI I / O requests, allowing for the amortization of storage resources-through a disk subsystem while maintaining coherency amongst I / O RAID traffic. In one embodiment, the virtualization functionality is implemented in a controller device, such as a controller card residing in a switch device or other network device, coupled to a storage system on a storage area network (SAN). The resulting virtual disk image that is observed by the host computer is larger than the amount of physical storage actually consumed.

A method and apparatus used in a storage network facilitates the protection of data in, and replacement of, storage devices about to fail before the failure happens. In a network that includes a set of storage devices organized as a non-redundant (for example RAID 0) array, a storage device about to fail in the non-redundant array can be replaced by another storage device, typically from a pool of spares. The method includes detecting a condition of a first particular storage device in the non-redundant array. Conditions which are detected according to various embodiments indicate that the first particular storage device is suffering events indicating that it is likely to fail, or otherwise suffering from reduced performance. The conditions are detected for example, by the receipt of a signal from the storage device itself, or by the monitoring of statistics concerning the performance of the storage device. The method further provides for selecting a particular spare storage device, which can be used in place of the first particular storage device. In response to detecting the condition, data stored in the first particular storage device is migrated to the second particular storage device, and the second particular storage takes the place of the first particular storage device in the non-redundant array. The first particular storage device can then be gracefully removed from the network without loss of service to the clients computers.

A write-caching RAID controller is disclosed. The controller includes a CPU that manages transfers of posted-write data from host computers to a volatile memory and transfers of the posted-write data from the volatile memory to storage devices when a main power source is supplying power to the RAID controller. A memory controller flushes the posted-write data from the volatile memory to the non-volatile memory when main power fails, during which time capacitors provide power to the memory controller, volatile memory, and non-volatile memory, but not to the CPU, in order to reduce the energy storage requirements of the capacitors. During main power provision, the CPU programs the memory controller with information needed to perform the flush operation, such as the location and size of the posted-write data in the volatile memory and various flush operation characteristics.

A non-volatile memory data storage system, comprising: a host interface for communicating with an external host; a main storage including a first plurality of flash memory devices, wherein each memory device includes a second plurality of memory blocks, and a third plurality of first stage controllers coupled to the first plurality of flash memory devices; and a second stage controller coupled to the host interface and the third plurality of first stage controller through an internal interface, the second stage controller being configured to perform RAID operation for data recovery according to at least one parity.

A system and method for adaptive RAID geometries. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array is configured to determine a first RAID layout for use in storing data, and write a first RAID stripe to the device group according to the first RAID layout. In response to detecting a first condition, the controller is configured to determine a second RAID layout which is different from the first RAID layout, and write a second RAID stripe to the device group according to the second layout, whereby the device group concurrently stores data according to both the first RAID layout and the second RAID layout.

A data storage methodology wherein a data file is initially stored in a format consistent with RAID-1 and RAID-X and then migrated to a format consistent with RAID-X and inconsistent with RAID-1 when the data file grows in size beyond a certain threshold. Here, RAID-X refers to any non-mirrored storage scheme employing XOR-based error correction coding (e.g., a RAID-5 configuration). Each component object (including the data objects and the parity object) for the data file is configured to be stored in a different stripe unit per object-based secure disk. Each stripe unit may store, for example, 64 KB of data. So long as the data file does not grow beyond the size threshold of a stripe unit (e.g., 64 KB), the parity stripe unit contains a mirrored copy of the data stored in one of the data stripe units because of the exclusive-ORing of the input data with “all zeros” assumed to be contained in empty or partially-filled stripe units. When the file grows beyond the size threshold, the parity stripe unit starts storing parity information instead of a mirrored copy of the file data. Thus, the data file can be automatically migrated from a format consistent with RAID-1 and RAID-X to a format consistent with RAID-X and inconsistent with RAID-1 without the necessity to duplicate or rewrite the stored data.

The invention is intended to reduce disk access during data transfer from a disk in which occurrence of failure is anticipated to a spare disk as much as possible so that occurrence of double-failure is prevented in advance. When occurrence of failure in a disk which configures a RAID group, contents stored in the disk is copied to the spared disk. Simultaneously, another RAID group is paired with the above described RAID group and a secondary volume is provided therein. A write request is directed to the secondary volume. A differential bitmap controls a update data. Data which is not updated is read out from the primary volume, and data which is already updated is read from the secondary volume. When data transfer is completed, contents stored in the secondary volume are copied to the primary volume.

The present disclosure relates to systems and methods for RAID Restriping. One method includes selecting an initial RAID device for migration based on at least one score, creating an alternate RAID device, moving data from the initial RAID device to the alternate RAID device, and removing the initial RAID device. The method may be performed automatically by the system or manually. The method may be performed periodically, continuously, after every RAID device migration, upon addition of disk drives, and / or before removal of disk drives, etc. One system includes a RAID subsystem and a disk manager configured to automatically calculate a score for each RAID device, select a RAID device based on the relative scores of the RAID devices, create an alternate RAID device, move data from the selected RAID device to the alternate RAID device, and remove the selected RAID device.

A storage system using flash memories includes a storage controller and plural flash memory modules as storage media. Each flash memory module includes at least one flash memory chip and a memory controller for leveling erase counts of blocks belonging to the flash memory chip. The storage controller combines the plural flash memory modules into a first logical group, translates a first address used for accessing the flash memory modules belonging to the first logical group to a second address used for handling the first address in the storage controller, and combines the plural first logical groups into a second logical group.

A user configurable RAID system designed to provide RAID functions as well as mass storage functions in a non-RAID mode. Flexibility is built into the system to allow the user to configure the SCSI bus to which removable drive modules are connected into one or more channels to define some of the drive modules in a RAID set and others as stand-alone drives which are independently operated or logically grouped and operated in a non-RAID mode. Removable internal SCSI bridges allow the SCSI bus to be configured into one or more channels. In the RAID mode, the system is configured to prevent a wrong drive from being removed from the system in the event of a drive failure. The system automatically unlatches only the failed drive. The RAID system includes an intelligent control unit ("ICU"), a RAID controller and a modem. The ICU allows the system administrator to access the RAID system Monitor Utility so that the status of the system may be monitored and its configuration changed. The ICU also monitors the failure status of the various components of the system. The ICU has a built-in pager feature that can be configured with the Monitor Utility to page the system administrator via the modem when a component or system failure is encountered. The RAID controller controls the functions of the RAID set as programmed and configured using the Monitor Utility. The Monitor Utility may be remotely accessed using a computer via the modem. Redundant removable power supply and fan units are provided to improve system integrity. The removable power supply and fan units are configured such when the unit is plugged into the system housing, the fan is first turned on and the power through the unit is allowed to stabilize before turning on the power supply to begin providing DC power to the components in the system. A set of manual release buttons are provided for manually unlatching the drive modules from the system housing. A locking mechanism is provided for simultaneously locking all the manual release buttons.

Embodiments of the present invention are broadly directed to a memory system. In one embodiment, a first data memory is coupled to a first memory controller and a second data memory is coupled to a second memory controller. A parity memory is coupled to a parity controller, the parity controller being directly coupled to both the first memory controller and the second memory controller. Parity data control logic is configured to store and retrieve parity information associated with data stored in both the first data memory and the second data memory, the parity data control logic configured to interleave within the parity memory parity data associated with data stored in the first data memory with parity data associated with data stored in the second data memory.