Abstract: Embodiments of the invention provide techniques for managing cache metadata providing a mapping between addresses on a storage medium (e.g., disk storage) and corresponding addresses on a cache device at data items are stored. In some embodiments, cache metadata may be stored in a hierarchical data structure comprising a plurality of hierarchy levels. When a reboot of the computer is initiated, only a subset of the plurality of hierarchy levels may be loaded to memory, thereby expediting the process of restoring the cache metadata and thus startup operations. Startup may be further expedited by using cache metadata to perform operations associated with reboot. Thereafter, as requests to read data items on the storage medium are processed using cache metadata to identify addresses at which the data items are stored in cache, the identified addresses may be stored in memory.

Abstract: A RAID system is provided in which the RAID controller of the system causes a predetermined number, N, of IO commands to be queued in a memory element, where N is a positive integer. After the N IO commands have been queued, the RAID controller writes N locks associated with the N IO commands in parallel to a service memory device. The RAID controller then writes N stripes of data and parity bits associated with the N IO commands to the PDs of the system to perform striping and parity distribution. If a catastrophic event, such as a power failure, occurs, the RAID controller reads the locks from the service memory device and causes parity to be reconstructed for the stripes associated with the locks. These features improve write performance while preventing the occurrence of data corruption caused by write holes.

Abstract: This Sampling Object Cache System (“SOCS”) estimates the size of an in-memory heap-based object cache without the need to serialize every object within the cache. SOCS samples objects at a user-determined rate and then computes a “sample size average” for each type of class—whether a top class, type of top class or non top class. Using these sample size averages, a statistically accurate measure of the overall size of the cache is calculated by adding together the total size of the objects in the cache for each class type.

Abstract: Approaches for improving writing to solid state devices. An object cache or store, maintained on one or more flash storage devices, comprises two or more slabs. A slab is an allocated amount of memory for storing objects of a particular size. A request to write requested data to a slab is received. The size of the requested data is less than the maximum capacity of objects stored in the slab. After writing the requested data to the slab, unrequested data is written up to the maximum capacity of an object in the slab in the same write operation. Writing the unrequested data to the particular slab is performed for purposes of reducing the time required to write the requested data to the SSD.

Abstract: A storage system comprising a storage apparatus having a storage control unit communicatively coupled to an external apparatus, forming a plurality of virtual storage areas each serving as a unit storage area used by the external apparatus as a data storing area, using a unit logical storage area selected among a plurality of unit logical storage areas provided by a physical storage medium, linking to each of the virtual storage areas, and any one of a plurality of attributes each representing a storage state of data stored in the virtual storage area, and maintaining the link wherein the storage control unit 11 further includes a logical storage area management unit 1140 that manages the link of the virtual storage area and any one of the attributes to each of logical storage area groups each configured to include the unit logical storage area to maintain the link and manage the linking relation, wherein the logical storage area management unit 1140, when receiving a command to change an attribute of any one

Abstract: To migrate data from a first storage system to a second storage system, the second storage system detects a migration of a persistent storage media from the first storage system to the second storage system. In response to detecting the migration of the persistent storage media, write information from a write cache in the first storage system is copied to a write cache in the second storage system, where the write caches in the first and second storage systems were not maintained synchronously before the write information from the write cache in the first storage system is copied to the write cache in the second storage system.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: In a system and method for a storage area network (SAN), a first controller receives a write request for a SAN an communicates with a first nested storage array module (NSAM), the first NSAM manages storage of data onto a shelf and presents the shelf as a logical unit, a buffer stores a portion of a write request from the first controller and aggregates data from the write request for the shelf, from a shelf with a second NSAM, the second NSAM provides a portion of data from the buffer to a third NSAM, the third NSAM manages storage of the portion of data from the buffer to a physical storage unit, and a second controller coupled to the first controller handles requests for the SAN in response to a failure of the first controller.

Abstract: Realigning storage devices arranged as storage arrays when one of the storage arrays enters a critical state after failure of a storage device is disclosed. The method is particularly useful for RAID groups of storage devices. The method may be used with hard disk drives, solid-state drives, and other storage devices arranged as groups. The method includes identifying that a storage array of a plurality of storage arrays is in a critical condition. A critical condition storage array and a healthy storage array are identified. Both the critical condition storage array and the healthy storage array are rebuilt. The rebuilding includes configuring the critical condition storage array to include a storage device from the healthy storage array and configuring the healthy storage array to function with one less storage device. The method may be implemented in hardware, firmware, software, or a combination thereof.

Abstract: An apparatus, system, and method are disclosed for solid-state storage as cache for high-capacity, non-volatile storage. The apparatus, system, and method are provided with a plurality of modules including a cache front-end module and a cache back-end module. The cache front-end module manages data transfers associated with a storage request. The data transfers between a requesting device and solid-state storage function as cache for one or more HCNV storage devices, and the data transfers may include one or more of data, metadata, and metadata indexes. The solid-state storage may include an array of non-volatile, solid-state data storage elements. The cache back-end module manages data transfers between the solid-state storage and the one or more HCNV storage devices.

Abstract: A disk array device includes, a cache memory, a plurality of types of disk drives of which data transfer capacity are different, redundant transmission paths that are data transfer paths between the cache memory and the disk drives, and a controller to divide the disk drives into two groups based on the data transfer capacity and allocate each of the two groups to each of the redundant transmission paths when the disk drives have three types.

Abstract: A disk array device includes a control unit which sends and receives a command and data to/from a host device, and in case a first disk device which constitutes RAID is stopped, controls so that data which is to be written from the host device to the stopped first disk device is written to a second disk device different from the first disk device.

Abstract: The storage control device of the present invention uses a plurality of queues to manage cache segments which are in use, so as to retain cache segments which contain large amounts of data for long periods of time. One of the queues manages segments in which large amounts of valid data are stored. Another queue manages segments in which small amounts of valid data are stored. If the number of unused segments becomes insufficient, then a segment which is positioned at the LRU end of the other queue is released, and is shifted to a free queue. Due to the use of this other queue, it is possible to retain segments in which comparatively large amounts of data are stored for comparatively long periods of time.

Abstract: Provided are a method, system, and article of manufacture for managing write requests to data sets in a primary volume subject to being copied to a secondary volume. Information indicating data sets to copy from a primary storage to a secondary storage is generated. A write request is received to write data to a target data set indicated in the information to copy from the primary storage to the secondary storage. A determination is made as to whether the write request is part of a sequential write access. The target data set and sequential data sets following the target data set are copied from the primary storage to the secondary storage. The write request to write the data to the primary storage is executed in response to receiving acknowledgment that the target data set was copied to the secondary storage.

Abstract: A RAID system to transfer data to and from host equipment includes a semiconductor storage unit, a semiconductor-memory selector, and a memory controller. The semiconductor storage unit includes two or more semiconductor memories, a mounting board, and solder joints. The semiconductor memories are mounted on the mounting board. The solder joints are between the semiconductor memories and the mounting board. The semiconductor-memory selector selects a combination of the semiconductor memories to dispersively record the data in the semiconductor storage unit. The memory controller accesses the combination in response to a request of the host equipment. In addition, the selector selects the combination so that mechanical loads received by the semiconductor memories are averaged.

Abstract: A storage system includes: a plurality of storing means and a data processing means that stores data into the plurality of storing means and retrieves the data stored in the storing means. The data processing means includes: a data set generating means that generates division data by dividing storage target data into a plurality of pieces and also generates redundant data for restoring the storage target data, thereby generating a data set composed of a plurality of fragment data that are the division data and the redundant data; and a distribution storage controlling means that distributes and stores the fragment data into the respective storing means. The distribution storage controlling means stores the fragment data composing the data set in same positions within storage regions formed in the respective storing means, respectively.

Abstract: A storage apparatus and its control method capable of shortening data save time at the time of power shutdown are suggested. The storage apparatus includes a processor for controlling reading/writing user data from/to a disk device(s), and a cache memory for storing user data sent and received between a channel adapter and a the disk adapter and control data used by the processor, wherein the control data is sorted into and stored in the nonvolatile memory or the volatile memory according to its update frequency.

Abstract: For the purpose of reducing the time for information processing in an array type disk device provided with a plurality of optical disk devices, when a beginning address is notified from any one of the optical disk devices to a main control device of the array type disk device, the main control device determines the beginning address notified first as a writing start address, without waiting for a notification of a beginning address from any other optical disk devices. Then, the main control device notifies the determined writing start address to the respective optical disk devices. Accordingly, even if search times for the writing start address are different among the optical disk devices, all the optical disk devices can start the writing of information based on which optical disk device has most quickly notified the beginning address.

Abstract: A server supporting the implementation of virtual machines includes a local memory used for caching, such as a solid state device drive. During I/O intensive processes, such as a boot storm, a “content aware” cache filter component of the hypervisor of the server first accesses a cache structure in a content cache device to determine whether data blocks have been stored in the cache structure prior to requesting the data blocks from a networked disk array via a standard I/O stack of the hypervisor. The content aware cache filter component is implemented in an I/O virtualization layer of the standard I/O stack that sits above a file system layer of the standard I/O stack, such that any file system protocol may be implemented in the file system layer.

Abstract: Disclosed is a RAID data checking system. I/O controllers to read data RAID data from the storage devices and transfer that data to virtual memory address ranges. The P+Q checking function receives the data sent to the virtual memory address ranges. However, instead of storing the incoming data, the P+Q checking function updates intermediate values of the P and Q redundant data calculations associated with the incoming data. When all of the strips have been received, the P+Q checking function will have completed the calculation of P and Q redundant data. In this case, after all the strips and the P or Q data have been received, the P+Q checking function will hold zeroes if all the data and the P and Q data was correct and hold non-zero values if there was an error.

Abstract: Systems and methods disclosed herein substantially concurrently transfer a plurality of streams of commands, addresses, and/or data across a corresponding plurality of serialized communication link interfaces (SCLIs) between one or more originating devices or destination devices such as a processor and a switch. At the switch, one or more commands, addresses, or data corresponding to each stream can be transferred to a corresponding destination memory vault controller (MVC) associated with a corresponding memory vault. The destination MVC can perform write operations, read operations, and/or memory vault housekeeping operations independently from concurrent operations associated with other MVCs coupled to a corresponding plurality of memory vaults.

Abstract: Some embodiments are directed to a technique for storing and/or locating content units stored on an object addressable storage (OAS) system, wherein each content unit is identified by an object identifier. The OAS system may comprise a plurality of zones, each of which stores content units. A mapping process may be defined that maps object identifiers for content units to zones on the OAS system. Thus, the storage location for a content unit on the OAS system may be the zone on the OAS system to which the object identifier for the content unit maps.

Abstract: A method of setting up a redistribution scheme for redistributing digital data packages within a digital data storage system comprising a plurality of nodes, wherein the data packages are associated with respective keys and are distributed among the nodes according to a first distribution configuration within the digital data storage system. The method includes: determining a second distribution configuration, in accordance with which it is intended to redistribute the data packages; applying a migration function to the respective keys of each of the data packages, which function yields a migration value associated with each of the data packages; and assigning a migration time to each of the data packages based on its associated migration value, at which times it is intended to migrate the respective data packages to conformity with the second distribution configuration. A corresponding digital data storage system is described.

Abstract: A disk drive system and method capable of dynamically allocating data is provided. The disk drive system may include a RAID subsystem having a pool of storage, for example a page pool of storage that maintains a free list of RAIDs, or a matrix of disk storage blocks that maintain a null list of RAIDs, and a disk manager having at least one disk storage system controller. The RAID subsystem and disk manager dynamically allocate data across the pool of storage and a plurality of disk drives based on RAID-to-disk mapping. The RAID subsystem and disk manager determine whether additional disk drives are required, and a notification is sent if the additional disk drives are required. Dynamic data allocation and data progression allow a user to acquire a disk drive later in time when it is needed. Dynamic data allocation also allows efficient data storage of snapshots/point-in-time copies of virtual volume pool of storage, instant data replay and data instant fusion for data backup, recovery etc.

Abstract: A disk drive system and method capable of dynamically allocating data is provided. The disk drive system may include a RAID subsystem having a pool of storage, for example a page pool of storage that maintains a free list of RAIDs, or a matrix of disk storage blocks that maintain a null list of RAIDs, and a disk manager having at least one disk storage system controller. The RAID subsystem and disk manager dynamically allocate data across the pool of storage and a plurality of disk drives based on RAID-to-disk mapping. The RAID subsystem and disk manager determine whether additional disk drives are required, and a notification is sent if the additional disk drives are required. Dynamic data allocation and data progression allow a user to acquire a disk drive later in time when it is needed. Dynamic data allocation also allows efficient data storage of snapshots/point-in-time copies of virtual volume pool of storage, instant data replay and data instant fusion for data backup, recovery etc.

Abstract: A virtual storage method and a device are disclosed. The virtual storage method includes: obtaining a volume management mode of a Logical Unit Number (LUN) from a storage array and recording the volume management mode into stitch data; and constructing a virtual LUN according to the LUN and the stitch data, and mapping the virtual LUN to a host to enable read/write access; and modifying a destination address of an Input/Output (I/O) data packet delivered by the host according to the stitch data after receiving the I/O data packet, delivering the I/O data packet to the virtual LUN, and delivering the I/O data packet which has been delivered to the virtual LUN to the storage array according to the stitch data, where an address of the storage array to which the I/O data packet is delivered is the same as the destination address of the I/O data packet before the destination address of the I/O data packet is modified.

Abstract: Methods and apparatus for cut-through cache memory management in write command processing on a mirrored virtual volume of a virtualized storage system, the virtual volume comprising a plurality of physical storage devices coupled with the storage system. Features and aspects hereof within the storage system provide for receipt of a write command and associated write data from an attached host. Using a cut-through cache technique, the write data is stored in a cache memory and transmitted to a first of the plurality of storage devices as the write data is stored in the cache memory thus eliminating one read-back of the write data for transfer to a first physical storage device. Following receipt of the write data and storage in the cache memory, the write data is transmitted from the cache memory to the other physical storage devices.

Abstract: The flash file system includes a flash memory and a subsystem interfacing between the flash memory and a host system. The subsystem includes a hierarchical structure of a host system interface, cache memory system, flash translation layer unit and a flash memory interface. The host system interface interfaces with the host system. The cache memory system has a storage capacity of a predetermined number of data units and stores data for transfer to and from the host system via the host system interface. The flash translation layer unit maps a logical address received from the host system via the host system interface and the cache memory into a physical address of the flash memory.

Abstract: Even if an arbitrary hard disk drive is added, the hard disk drive is operated in a specific operation mode suited for that hard disk drive. As triggered by attachment of a hard disk drive to a disk adapter, a processor operates the hard disk drive in a predetermined operation mode based on predetermined parameter information that has been prepared in advance. The hard disk drive stores, in advance, particular parameter information including information about the specific operation mode suited for operation. The processor reads the particular parameter information from the hard disk drive in the predetermined operation mode and operates the hard disk drive in the specific operation mode based on the particular parameter information.

Abstract: Provided are a storage system and a method of controlling a storage system in which respective real storage areas of a plurality of disk drives contained in the storage system contain management units, and a control device of the storage system assigns a real storage area of a plurality of first disk drives to the virtual storage area, distributedly stores the data in the plurality of management units of the assigned real storage area, distributedly stores, upon receiving a request for adding a second disk drive, the data stored in the plurality of management units of the plurality of first disk drives in the plurality of management units of the plurality of first disk drives and the second disk drive, and assigns the real storage area of the plurality of first disk drives and the second disk drive to an unused virtual storage area.

Abstract: A storage controller that can maintain its performance and reduce power consumption and thereby realize large capacity and low power consumption, and a method for controlling such a storage controller are provided. The storage controller includes: a plurality of nonvolatile memory modules having a plurality of nonvolatile memory chips for storing data from a host computer; and a nonvolatile memory control unit for controlling data input to and output from the host computer by controlling a power source for the nonvolatile memory modules; wherein when reading or writing data from or to a designated nonvolatile memory module at a specified time in response to a data read/write request from the host computer, the nonvolatile memory control unit controls the power source for only the designated nonvolatile memory module to be turned on.

Abstract: Storage optimization selection for virtual disks of a virtualization environment, where the storage optimization can be selected based in part on the disk type of a virtual disk included in a virtual machine. The disk type of the virtual disk can be discovered by the virtualization environment which queries a database within the virtualization environment for metadata associated with the virtual disk. The metadata can be created when a virtual desktop infrastructure creates the virtual disk, and a virtual machine template that includes the at least one virtual disk. The virtual disk can be modified to either include or be associated with the metadata that describes a disk type of the virtual disk. Upon executing the virtual machine that includes the modified virtual disk, a storage subsystem of the virtualization environment can obtain the metadata of the virtual disk to discover the disk type of the virtual disk.

Abstract: Systems and methods of monitoring logical block address (LBA) activity are disclosed. In an embodiment, a pattern of a data storage device may be monitored. An LBA may be detected that is accessed based on the pattern. The LBA may be added to a list of LBAs stored in a memory.

Abstract: In a disc device according to the present invention, when a controller 2 abandons a block from a cache memory 4 used as a primary cache, it is determined whether or not the number of readings of data in the block exceeds the specified number of times. Only when the number of readings exceeds the specified number of times, the block is written into an SSD 8 used as a secondary cache. When the number of readings is equal to or smaller than the specified number of times, the block is rewritten into an HDD 7.

Abstract: In one embodiment, a method for writing data to a magnetic recording tape includes writing a plurality of files to a first partition of a magnetic recording tape using a tape drive, and writing an index to a second partition of the magnetic recording tape using the tape drive, the index including information about locations of data of the plurality of files in the first partition of the magnetic recording tape.

Abstract: A method and apparatus for deferring media writes for emulation drives are provided. By deferring media writes using non-volatile storage, the performance penalty associated with RMW operations may be minimized. Deferring writes may allow the RMW operations to be done while the disk drive is idle. Further, deferring writes may also allow data blocks to be accumulated over time, allowing a full (4K) disk drive block size to be written with a simple write operation, thus making a RMW unnecessary.

Abstract: A storage apparatus sets up part of non-volatile cache memory as a cache-resident area, and in an emergency such as an unexpected power shutdown, backs up dirty data of data cached in volatile memory to an area other than the cache-resident area in the non-volatile cache memory, together with the relevant cache management information. Further, the storage apparatus monitors the amount of the dirty data in the volatile cache memory so that the dirty data cached in the volatile cache memory is reliably contained in a backup area in the non-volatile memory, and when the dirty data amount exceeds a predetermined threshold value, the storage apparatus releases the cache-resident area to serve as the backup area.

Abstract: A block device driver performs system boot using cache data and thus provides a mechanism that reduces disk/IO waiting time during system boot.

Abstract: The invention proposes a disk array device that can improve response performance while maintaining data consistency even in the case a write request is received from a host device by a controller that does not have master authority. The disk array device includes a master controller and a slave controller. Upon adding identifying information indicating that write data has been stored in a buffer memory to the write request, the slave controller transmits, to the master controller, the write request to which the identifying information has been added as well as the write data. After having stored the write data, the master controller transmits the write request to which the identifying information has been added to the slave controller. Upon receiving the write request, the slave controller alters the attributes of the buffer memory where the write data has been stored, from the buffer memory to the cache memory.

Abstract: In at least some embodiments, a computing system includes a processor and a communication bus external to the processor. The computing system also includes a Redundant Array of Independent Disks (RAID) write cache sub-assembly coupled to the communication bus, the RAID write cache sub-assembly having non-volatile memory.

Abstract: An apparatus, system, and method are disclosed for solid-state storage as cache for high-capacity, non-volatile storage. The apparatus, system, and method are provided with a plurality of modules including a cache front-end module and a cache back-end module. The cache front-end module manages data transfers associated with a storage request. The data transfers between a requesting device and solid-state storage function as cache for one or more HCNV storage devices, and the data transfers may include one or more of data, metadata, and metadata indexes. The solid-state storage may include an array of non-volatile, solid-state data storage elements. The cache back-end module manages data transfers between the solid-state storage and the one or more HCNV storage devices.

Abstract: Methods and apparatus to detect a data mining process are presented. In one embodiment the method comprising monitoring access of a process to a resource and classifying if the process is a data mining process based on at least one of a plurality of monitored values, such as an access rate, an eviction rate, and an I/O consumption value.

Abstract: A method for committing cached data to storage media including a host entity and a physical storage device (PSD), comprising: the host entity issuing a write IO request to the PSD being in write-back caching mode to write data from a host memory to the PSD; the host entity receiving a successful IO completion response associated with the write IO request from the PSD and recording an entry of the write IO request to a selected list; the host entity issuing a synchronized cache IO request to the PSD; the PSD responding a successful IO completion response of the synchronized cache IO request to the host entity; the host entity extracting the entry of the write IO request from the selected list before issuing the synchronized cache IO request; and the host entity engaging completion processing of write IO request corresponding to the entry of the write IO request extracted.

Abstract: A disk formatter (DF) for a rotating storage medium includes a target sector identification module that determines a block of target sectors of the rotating storage medium based on a read/write command signal. A current sector identification module determines a current sector of a read/write head. A DF control module begins a read/write operation at a command start sector that is different than a first sector of the block of target sectors. The command start sector is located within the block of target sectors.

Abstract: A non-volatile hard disk drive cache system is coupled between a processor and a hard disk drive. The cache system includes a control circuit, a non-volatile memory and a volatile memory. The control circuit causes a subset of the data stored in the hard disk drive to be written to the non-volatile memory. In response to a request to read data from the hard disk drive, the control circuit first determines if the requested read data are stored in the non-volatile memory. If so, the requested read data are provided from the non-volatile memory. Otherwise, the requested read data are provided from the hard disk drive. The volatile memory is used as a write buffer and to store disk access statistics, such as the disk drive locations that are most frequently read, which are used by the control circuit to determine which data to store in the non-volatile memory.

Abstract: For each of a plurality of memory access routines having different access timing characteristic, a redundant array of independent disk (RAID) stack executes the memory access routine to load predetermined data from a main memory to a register of a processor of a data processing system. The RAID stack determines an amount of cache misses for the execution of the memory access routine. The RAID stack selects one of the plurality of memory access routines that has the least amount of cache misses for further memory accesses for the purpose of parity calculations of RAID data.

Abstract: A redundant array of independent disk (RAID) stack determines a first number of processor cycles to reload first data from a first memory address of a main memory into a processor of a data processing system. The RAID stack loads second data from a second memory address of the main memory into the processor, where the second memory address is configured to be an address offset from the first memory address. The RAID stack reloads the first data from the first memory address of the main memory and determines a second number of processor cycles to reload the first data from the first memory address of the main memory. An alias offset of a cache memory associated with the processor of the data processing system is determined based on the first number of processor cycles and the second number of processor cycle.

Abstract: A redundant array of independent disk (RAID) stack loads a first parity block of RAID data into a first memory address of a main memory of a data processing system. A first parity calculation is performed on a first plurality of data blocks of the RAID data with the first parity block loaded from the first memory address of the main memory into a register of the processor of the data processing system and a cache memory associated with the processor. The RAID stack loads subsequent parity blocks of RAID data into subsequent memory addresses of the main memory, where a difference between the first memory address and the subsequent memory addresses equals to one or more multiples of an alias offset associated with the cache memory. A second parity calculation is performed on a second plurality of data blocks and the second parity block of the RAID data.

Abstract: A redundant array of independent disk (RAID) stack loads a parity block of RAID data from a main memory into a first register of a processing device and loading the parity block into a cache memory of the processing device. The RAID stack loads a first data block of the RAID data from the main memory into a second register of the processing device without loading the first data block into the cache memory of the processing device. The processing device performs a first parity calculation based on the parity block of the first register and the first data block of the second register.

Abstract: According to one aspect of the invention, a method of controlling a storage system comprises storing data in a first volume in the storage system which has volumes including the first volume and a plurality of second volumes; prohibiting write I/O (input/output) access against the first volume after storing the data in the first volume; performing subsequent write requests received by the storage system against the second volumes in the storage system after storing the data in the first volume, each write request having a target volume which is one of the second volumes; and in response to each one write request of the write requests, determining whether the target volume of the one write request is write prohibited or not, and performing the one write request only if the target volume is not write prohibited.