Abstract: Operating a data storage system comprising a plurality of disk drives and a storage controller connected to the disk drives. A first subset and a second subset of the plurality of disk drives are operated as short stroked disk drives and non-short stroked disk drives, respectively. Priority storage spaces are defined including a high priority storage space, a medium priority storage space, and a low priority storage space. Data is received including associated access rates for each portion of the data. One of the priority storage spaces is identified to store a portion of the data, based on the access rates for each portion of the data. Data accessed most frequently is stored in the high priority storage space, data accessed least frequently is stored in the low priority storage space, and the remaining data is stored in the medium priority storage space.

Abstract: The various embodiments relate to a storage system, storage system method and computer program product including: providing a distributed collection of drives, each drive having logical blocks, each logical block being assignable to a segment with an associated volume and being configurable to RAID characteristics associated with that volume; assigning a first group of logical blocks to a segment with an associated volume and configuring the first group of logical blocks to RAID characteristics associated with that volume; and wherein a further group of logical blocks is ready to be assigned to any segment but is not yet assigned.

Abstract: Method and system are provided for handling an underperforming drive in a redundant array of independent disks (RAID) operating a distributed sparing mechanism. The method includes marking an underperforming drive in the array as resting and allocating distributed spare space of the array for data of operations to the resting drive. A data structure is designated to track operations diverted to the distributed spare space from the resting drive. If the resting drive is recovered, the method rebuilds data to the recovered drive from the distributed spare space by reference to the data structure.

Abstract: A RAID controller may update a RAID array by receiving updated data for a first data strip in a set of data strips in the RAID array. The RAID controller may then determine that the first data strip is stored on a device that is experiencing a slow condition. The RAID controller may then force, based on the determining, a promoted stripe write.

Abstract: Method and system are provided for handling an underperforming drive in a redundant array of independent disks (RAID) operating a distributed sparing mechanism. The method includes marking an underperforming drive in the array as resting and allocating distributed spare space of the array for data of operations to the resting drive. A data structure is designated to track operations diverted to the distributed spare space from the resting drive. If the resting drive is recovered, the method rebuilds data to the recovered drive from the distributed spare space by reference to the data structure.

Abstract: A RAID controller may update a RAID array by receiving updated data for a first data strip in a set of data strips in the RAID array. The RAID controller may then determine that the first data strip is stored on a device that is experiencing a slow condition. The RAID controller may then force, based on the determining, a promoted stripe write.

Abstract: Operating a data storage system comprising a plurality of disk drives and a storage controller connected to the disk drives. A first subset and a second subset of the plurality of disk drives are operated as short stroked disk drives and non-short stroked disk drives, respectively. Priority storage spaces are defined including a high priority storage space, a medium priority storage space, and a low priority storage space. Data is received including associated access rates for each portion of the data. One of the priority storage spaces is identified to store a portion of the data, based on the access rates for each portion of the data. Data accessed most frequently is stored in the high priority storage space, data accessed least frequently is stored in the low priority storage space, and the remaining data is stored in the medium priority storage space.

Abstract: A storage drive array with available storage space for user data with storage capacity in the array allocated to distributed spare space. The distributed spare space spreads portions of a spare drive across multiple storage drives in the array. By monitoring the amount of spare space available in the array, a determination may be whether the amount of spare space falls below a threshold number of drives. If there is un-used space in the available storage space which is greater than one drive of space, a drive of space to spare space may be dynamically re-allocated in a distributed pattern across the drives of the array.

Abstract: Data is stored on a primary storage system and a copy of the data is stored on a secondary storage system. A determination is made that a connection between the systems is currently unavailable. Location data is maintained that identifies where changes have been made to the primary storage system while the connection is unavailable. Another determination is made that data has been lost at the secondary storage system. Recovery data required to repair the lost data is identified. Another determination is made that the connection to the secondary storage system is now available. The location data is updated with the locations of the recovery data. The secondary storage system is updated with data from the primary storage system as defined by the location data.

Abstract: Operating a data storage system comprising a plurality of disk drives and a storage controller connected to the disk drives. A first subset and a second subset of the plurality of disk drives are operated as short stroked disk drives and non-short stroked disk drives, respectively. Priority storage spaces are defined including a high priority storage space, a moderate priority storage space, and a low priority storage space. Data is received including associated access rates for each portion of the data. One of the priority storage spaces is identified to store a portion of the data, based on the access rates for each portion of the data. Data accessed most frequently is stored in the high priority storage space, data accessed least frequently is stored in the low priority storage space, and the remaining data is stored in the moderate priority storage space.

Abstract: The various embodiments relate to a storage system, storage system method and computer program product including: providing a distributed collection of drives, each drive having logical blocks, each logical block being assignable to a segment with an associated volume and being configurable to RAID characteristics associated with that volume; assigning a first group of logical blocks to a segment with an associated volume and configuring the first group of logical blocks to RAID characteristics associated with that volume; and wherein a further group of logical blocks is ready to be assigned to any segment but is not yet assigned.

Abstract: This invention relates to a storage system, storage system method and computer program product comprising: providing a distributed collection of drives, each drive having logical blocks, each logical block being assignable to a segment with an associated volume and being configurable to RAID characteristics associated with that volume; assigning a first group of logical blocks to a segment with an associated volume and configuring the first group of logical blocks to RAID characteristics associated with that volume; and wherein a further group of logical blocks is ready to be assigned to any segment but is not yet assigned.

Abstract: Cache management. It is determined that a cache operation relating to the transfer of data between a cache memory and a data storage system is required. A state of a utilization model is received, the utilization model including requirements for utilization of resources of the data storage system over a time period, and the state indicating a cost of resource utilization associated with cache operations in the current time period. It is determined whether to perform the cache operation, based on the utilization requirements and the state of a utilization model. If the cache operation is not to be performed, and if the cache operation is a write operation, it is determined whether the cache memory is full. If so, the cache operation is managed according to an emergency cache management process; if not, the data associated with the cache operation is maintained in the cache memory.

Abstract: A method for minimizing head seek movement and improving I/O performance of a hard disk drive is disclosed. In one embodiment, such a method includes logically dividing storage space of a hard disk drive into storage areas of substantially equal size. The method monitors a temperature of each of the storage areas. The temperature indicates how frequently data in a corresponding storage area is accessed. The method swaps data in storage areas of the hard disk drive based on temperature. These swaps involve moving hotter data toward outer tracks of the disk drive and colder data toward inner tracks of the disk drive. A corresponding system and computer program product are also disclosed.

Abstract: Method and system are provided for storage capacity allocation. The method includes: providing a storage pool having multiple storage drive arrays; designating an initial available storage capacity in the storage pool; and allocating the remaining storage capacity in the storage pool to distributed spare space, wherein distributed spare space spreads portions of a spare drive across multiple storage drives in an array. The method also includes: monitoring an amount of available storage capacity as data is stored to the storage pool and determining when a threshold of a minimum available storage capacity is reached; and re-allocating one or more distributed spare drives from an array to available storage capacity when the threshold of the minimum available storage capacity is reached.

Abstract: Data is stored on a primary storage system and a copy of the data is stored on a secondary storage system. A determination is made that a connection between the systems is currently unavailable. Location data is maintained that identifies where changes have been made to the primary storage system while the connection is unavailable. Another determination is made that data has been lost at the secondary storage system. Recovery data required to repair the lost data is identified. Another determination is made that the connection to the secondary storage system is now available. The location data is updated with the locations of the recovery data. The secondary storage system is updated with data from the primary storage system as defined by the location data.

Abstract: This invention relates to a system, method and computer program product for a drive array controller (for example a RAID6 controller) comprising: a failed strip identifier for identifying a failed strip in a critical stride strip in drive array when the drive array has two or more failed drives, a critical stride is a stride with two (for example) failed strips, a failed strip is a strip in a failed drive, a failed drive is a drive that can no longer be reliably used; a safe strip identifier for identifying a safe strip in a safe stride, a safe stride is a stride with no failed strips (or at least two less than a critical stride), a safe strip is a strip in a safe stride; a drive array writer for writing a recalculated failed strip to the drive array location for the safe strip; and a lending table writer for writing the failed strip location and associated safe strip location to a lending table.

Abstract: A data storage system comprises a primary storage system comprising an array of drives and a storage controller comprising a stack of storage components. A storage component of the stack operates a data redundancy scheme for the primary storage system. The storage controller stores a set of data on the primary storage system, detects a failure on one or more drives and determines a set of addresses defining data that cannot be completely repaired. Starting with the storage component operating the data redundancy scheme, each storage component queries the storage component directly above with the set of addresses for the data that cannot be completely repaired, obtaining, from one or more storage components, the data that cannot be completely repaired. This obtained data is used to repair the data on the primary storage system with the data from the one or more storage components.

Abstract: A method for balancing performance in a redundant array of independent disks (RAID) made up of heterogeneous storage drives is disclosed. In one embodiment, such a method includes implementing a RAID on a set of storage drives. The set of storage drives includes a lower-performing storage drive that underperforms other storage drives in the set. In order to balance performance in the RAID, the method stripes data across the set of storage drives such that the lower-performing storage drive participates in only a selected percentage of strides. In certain embodiments, this percentage is selected based on an amount the lower-performing storage drive underperforms other storage drives in the set. A corresponding system and computer program product are also disclosed.

Abstract: Embodiments of the present invention disclose a method, computer program product, and system for managing a RAID array of data storage devices. The declustered RAID array is configured to tolerate a predetermined number of failing data storage devices. The declustered RAID array of data storage devices is split into a plurality of regions, each of the plurality of regions is divided into a plurality of sets, and each of the sets of the plurality of sets utilizes a different combination of the data storage devices. The declustered RAID array provisions a plurality of LUNs from respective sets of each of the plurality of regions, and in response to a failure of one or more of the plurality of data storage devices, up to the predetermined number of failing data storage devices, the RAID array rebuilds at least one copy of each of the plurality of virtual LUNs.