摘要:
Described are techniques for caching. At a first point in time, a first set of data portions currently stored in a first cache of a first data storage system is determined. Each data portion of the first set is located on a first device of the first data storage system. Sent to a second data storage system is first information including information identifying a storage location on the first device for each data portion of the first set. The second data storage system includes a second device that is maintained as a mirror of the first device. The storage location for each data portion of the first set is used to identify a second storage location of the second device corresponding to the storage location. The first information is used to populate a second cache of the second data storage system.
摘要:
Described are techniques for enforcing an allocation policy. Information is received that describes one or more storage groups. Each of the storage groups includes one or more thin devices. Each of the thin devices includes a plurality of chunks of storage allocated on one or more of a plurality of storage tiers. For each of the one or more storage groups, a plurality of counters is determined indicating amounts of storage currently allocated from the plurality of storage tiers for use by the storage group. Using the plurality of counters, it is determined whether each of the one or more storage groups violates thresholds included in an allocation policy associated with each storage group. Each of the thresholds specifies a maximum amount of storage of one of the plurality of storage tiers that can be used by each storage group.
摘要:
Guaranteeing space availability for thin devices includes reserving space without committing, or fully pre-allocating, the space to specific thin device ranges. Space may be held in reserve for a particular set of thin devices and consumed as needed by those thin devices. The system guards user-critical devices from running out of space, for example due to a “rogue device” scenario in which one device allocates an excessive amount of space. The system uses a reservation entity, to which a thin device may subscribe, which reserves space for the thin device without allocating that space before it is need to service an I/O request.
摘要:
A method, computer program product, and computing system for receiving a write request on a first cache system, wherein the write request identifies new content to be written to a data array. A write request content identifier associated with the new content is compared to a plurality of content identifiers included within a content directory for the first cache system to determine if a matching content identifier exists. Each of the plurality of content identifiers is associated with a piece of previously-written content included within the first cache system. If a matching content identifier is identified, content on the data array is copied from a first location on the data array associated with the matching content identifier to a second location on the data array associated with the write request content identifier.
摘要:
Described are techniques for configuring data storage. Criteria identifying limits is received for a plurality of storage tiers for one or more logical devices. The storage tiers include a first storage tier and one or more other storage tiers where the first storage tier is higher performing than the other storage tiers. First processing is performed to determine a first set of data portions of the logical devices to be stored on physical devices of the first storage tier subject to limits included in said criteria. First processing includes determining scores for data portions of the logical devices. Each score is calculated using one or more metrics including a first metric weighted based on an expected I/O size. The data portions are ranked in accordance with the scores. The first set of data portions stored in the first storage tier is selected based on the score ranking.
摘要:
A method, computer program product, and computing system for receiving a read request on a first cache system, wherein the read request identifies previously-written content included within a data array. A read request content identifier associated with the previously-written content identified in the read request is received from the data array. The read request content identifier associated with the previously-written content identified in the read request is compared to a plurality of content identifiers included within a content directory for the first cache system to determine if a matching content identifier exists. Each of the plurality of content identifiers is associated with a piece of previously-written content included within the first cache system.
摘要:
Described are techniques for tracking activity for one or more devices. Each of the one or more devices is partitioned into one or more extents. Each of the one or more extents includes a plurality of sub extents. Each of the sub extents includes a plurality of chunks. For each of said one or more extents of each of said one or more devices, extent activity level information is determined including one or more metrics indicating an activity level for said each extent; and For each of said one or more extents of each of said one or more devices, an activity bitmap is determined. The activity bitmap includes an entry for each sub extent included in said each extent, said entry indicating an activity level for said each sub extent.
摘要:
A system for normalizing capacity utilization within virtual storage pools includes collecting utilization statistics across individual storage devices that are members of a virtualized storage pool. Using the pool utilization level statistics, pool members may be assigned a score and, according to that score, may be marked as source, target or neutral members. Based on the scores of each pool member, data may be migrated among pool members, in particular, from source members to target members. The process may be iterative such that the statistics and scores may be used only to perform a fraction of the data movement that would be needed to normalize the storage pool before the scores are then recalculated. In this way, the system may dynamically adapt to changing conditions within the pool such as device additions, removals and inefficient striping of new data.
摘要:
A method, computer program product, and computing system for receiving an indication of a cold cache event within a storage system. The storage system includes a multi-tiered data array including at least a faster data tier and a slower data tier. A data list that identifies at least a portion of the data included within the faster data tier of the multi-tiered data array is obtained from the multi-tiered data array. At least a portion of the data identified within the data list is requested from the multi-tiered data array, thus defining the requested data. The requested data is received from the multi-tiered data array.
摘要:
A write operation writes first data to a target logical address range included in a first logical address range of a virtually provisioned device. It is determined that physical storage is not allocated for the target logical address range. First processing is performed to allocate a first portion of physical storage having a first corresponding logical address subrange that includes the target logical address range. The first portion is allocated from a physical device included in a first storage tier. The first processing includes selecting the first storage tier from multiple storage tiers in accordance with selection criteria including metrics characterizing an expected workload or level of activity for the first corresponding logical address subrange of the virtually provisioned device. Mapping information is updated to indicate that the first corresponding logical address subrange of the virtually provisioned device maps to the first portion of physical storage.