摘要:
A method is disclosed to manage a data cache. The method provides a data cache comprising a plurality of tracks, where each track comprises one or more segments. The method further maintains a first LRU list comprising one or more first tracks having a low reuse potential, maintains a second LRU list comprising one or more second tracks having a high reuse potential, and sets a target size for the first LRU list. The method then accesses a track, and determines if that accessed track comprises a first track. If the method determines that the accessed track comprises a first track, then the method increases the target size for said first LRU list. Alternatively, if the method determines that the accessed track comprises a second track, then the method decreases the target size for said first LRU list. The method demotes tracks from the first LRU list if its size exceeds the target size; otherwise, the method evicts tracks from the second LRU list.
摘要:
A technique for determining when to destage write data from a fast, NVS of a computer system from an upper level to a lower level of storage in the computer system comprises adaptively varying a destage rate of the NVS according to a current storage occupancy of the NVS; maintaining a high threshold level for the NVS; maintaining a low threshold level that is set to be a predetermined fixed amount below the high threshold; setting the destage rate of the NVS to zero when the NVS occupancy is below the low threshold; setting the destage rate of the NVS to be maximum when the NVS occupancy is above the high threshold; linearly increasing the destage rate of the NVS from zero to maximum as the NVS occupancy goes from the low to the high threshold; and adaptively varying the high threshold in response to a dynamic computer storage workload.
摘要:
A technique for determining when to destage write data from a fast, NVS of a computer system from an upper level to a lower level of storage in the computer system comprises adaptively varying a destage rate of the NVS according to a current storage occupancy of the NVS; maintaining a high threshold level for the NVS; maintaining a low threshold level that is set to be a predetermined fixed amount below the high threshold; setting the destage rate of the NVS to zero when the NVS occupancy is below the low threshold; setting the destage rate of the NVS to be maximum when the NVS occupancy is above the high threshold; linearly increasing the destage rate of the NVS from zero to maximum as the NVS occupancy goes from the low to the high threshold; and adaptively varying the high threshold in response to a dynamic computer storage workload.
摘要:
A technique for determining when to destage write data from a fast, NVS of a computer system from an upper level to a lower level of storage in the computer system comprises adaptively varying a destage rate of the NVS according to a current storage occupancy of the NVS; maintaining a high threshold level for the NVS; maintaining a low threshold level that is set to be a predetermined fixed amount below the high threshold; setting the destage rate of the NVS to zero when the NVS occupancy is below the low threshold; setting the destage rate of the NVS to be maximum when the NVS occupancy is above the high threshold; linearly increasing the destage rate of the NVS from zero to maximum as the NVS occupancy goes from the low to the high threshold; and adaptively varying the high threshold in response to a dynamic computer storage workload.
摘要:
A set of logical extents, each having compressed logical tracks of data, is mapped to a head physical extent and, if the head physical extent is determined to have been filled, to at least one overflow extent having spatial proximity to the head physical extent. Pursuant to at least one subsequent write operation and destage operation, the at least one subsequent write operation and destage operation determined to be associated with the head physical extent, the write operation is mapped to one of the head physical extent, the at least one overflow extent, and an additional extent having spatial proximity to the at least one overflow extent.
摘要:
A system includes a write cache configured to store a plurality of storage tracks and configured to be coupled to one or more hosts, and a processor coupled to the write cache. The processor includes code that, when executed by the processor, causes the processor to perform the method below. One method includes monitoring the write cache for write operations from the host(s) and determining if the host(s) is/are idle based on monitoring the write cache for write operations from the host(s). The storage tracks are destaged from the write cache if the host(s) is/are idle and are not destaged from the write cache if one or more of the hosts is/are not idle. Also provided are physical computer storage mediums including a computer program product for performing the above method.
摘要:
Provided a computer program product, system, and method for cache management of tracks in a first cache and a second cache for a storage. The first cache maintains modified and unmodified tracks in the storage subject to Input/Output (I/O) requests. Modified and unmodified tracks are demoted from the first cache. The modified and the unmodified tracks demoted from the first cache are promoted to the second cache. The unmodified tracks demoted from the second cache are discarded. The modified tracks in the second cache that are at proximate physical locations on the storage device are grouped and the grouped modified tracks are destaged from the second cache to the storage device.
摘要:
Provided a computer program product, system, and method for cache management of tracks in a first cache and a second cache for a storage. The first cache maintains modified and unmodified tracks in the storage subject to Input/Output (I/O) requests. Modified and unmodified tracks are demoted from the first cache. The modified and the unmodified tracks demoted from the first cache are promoted to the second cache. The unmodified tracks demoted from the second cache are discarded. The modified tracks in the second cache that are at proximate physical locations on the storage device are grouped and the grouped modified tracks are destaged from the second cache to the storage device.
摘要:
A set of logical extents, each having compressed logical tracks of data, is mapped to a head physical extent and, if the head physical extent is determined to have been filled, to at least one overflow extent having spatial proximity to the head physical extent. Pursuant to at least one subsequent write operation and destage operation, the at least one subsequent write operation and destage operation determined to be associated with the head physical extent, the write operation is mapped to one of the head physical extent, the at least one overflow extent, and an additional extent having spatial proximity to the at least one overflow extent.
摘要:
Provided are a computer program product, system, and method for using an attribute of a write request to determine where to cache data in a storage system having multiple caches including non-volatile storage cache in a sequential access storage device. Received modified tracks are cached in the non-volatile storage device integrated with the sequential access storage device in response to determining to cache the modified tracks. A write request having modified tracks is received. A determination is made as to whether an attribute of the received write request satisfies a condition. The received modified tracks for the write request are cached in the non-volatile storage device in response to determining that the determined attribute does not satisfy the condition. A destage request is added to a request queue for the received write request having the determined attribute not satisfying the condition.