摘要:
A storage controller receives a request that corresponds to an access of a track. A determination is made as to whether the track corresponds to data stored in a solid state disk. Record staging to a cache from the solid state disk is performed, in response to determining that the track corresponds to data stored in the solid state disk, wherein each track is comprised of a plurality of records.
摘要:
Methods, systems, and physical computer-readable storage medium for processing a plurality of IO request jobs are provided. The method includes determining whether one or more request jobs are not meeting a QoS target, each job of the one or more request jobs having a corresponding priority, selecting a highest priority job from the one or more request jobs, if one or more request jobs are not meeting the QoS target, determining whether the highest priority job has a corresponding effective rate limit imposed thereon, if so, relaxing the corresponding effective rate limit, and if not, selecting one or more lower priority jobs from the one or more request jobs and tightening a corresponding effective limit on the one or more lower priority jobs from the one or more request jobs in accordance with a delay factor limit.
摘要:
For efficient track destage in secondary storage in a more effective manner, for temporal bits employed with sequential bits for controlling the timing for destaging the track in a primary storage, the temporal bits and sequential bits are transferred from the primary storage to the secondary storage. The temporal bits are allowed to age on the secondary storage.
摘要:
Method, system, and computer program product embodiments for, in a computing storage environment for destaging data from nonvolatile storage (NVS) to a storage unit, identifying working data on a stride basis by a processor device are provided. A multi-update bit is established for each of a plurality of strides in a modified cache, wherein the multi-update bit is adapted to indicate a corresponding stride is part of at least one track in a working set that refers to a group of frequently updated tracks. The plurality of strides are scanned based on a schedule to identify tracks for destaging. An operation to destage is performed on a selected track identified during the scanning, if the multi-update bit of a selected stride on the selected track is set to indicate the selected track is part of the working set and if the NVS is about 90% full or greater.
摘要:
A system and method for reducing device wait time in response to a host initiated write operation modifying a data block. The system includes a host computer channel connected to a storage controller which has cache memory and a nonvolatile storage buffer in a first embodiment. An identical system makes up the second embodiment with the exception that there is no nonvolatile storage buffer in the storage controller of the second embodiment. The controller in either embodiment is coupled to a cache storage drawer containing a plurality of DASD devices for implementing a RAID parity data protection scheme, and for permanently storing data. The drawer has nonvolatile cache memory which is used for accepting data destaged from controller cache. In a first embodiment, no commit reply is sent to the controller to indicate that data has been written to DASD. Instead a status information block is created to indicate that the data has been destaged from controller cache but is not committed. The status information is stored in directory means attached to the controller. The system uses this information to create a list of data which is in the state of Not committed. In this way data can be committed according to a cache management algorithm of least recently used (LRU), rather than requiring synchronous commit which is inefficient because it requires waiting on a commit response and ties up nonvolatile storage space allocated to back-up copies of cache data. In a second embodiment, directory means attached to the controller stores information about status blocks that may be modified or unmodified. The status information is used to eliminate wait times associated with waiting for data to be written to HDAs below.
摘要:
Methods, systems, and physical computer-readable storage medium for processing a plurality of IO request jobs are provided. The method includes determining whether one or more request jobs are not meeting a QoS target, each job of the one or more request jobs having a corresponding priority, selecting a highest priority job from the one or more request jobs, if one or more request jobs are not meeting the QoS target, determining whether the highest priority job has a corresponding effective rate limit imposed thereon, if so, relaxing the corresponding effective rate limit, and if not, selecting one or more lower priority jobs from the one or more request jobs and tightening a corresponding effective limit on the one or more lower priority jobs from the one or more request jobs in accordance with a delay factor limit.
摘要:
A storage controller receives a request that corresponds to an access of a track. A determination is made as to whether the track corresponds to data stored in a solid state disk. Record staging to a cache from the solid state disk is performed, in response to determining that the track corresponds to data stored in the solid state disk, wherein each track is comprised of a plurality of records.
摘要:
Exemplary method, system, and computer program product embodiments for efficient track destage in secondary storage in a more effective manner, are provided. In one embodiment, by way of example only, for temporal bits employed with sequential bits for controlling the timing for destaging the track in a primary storage, the temporal bits and sequential bits are transferred from the primary storage to the secondary storage. The temporal bits are allowed to age on the secondary storage. Additional system and computer program product embodiments are disclosed and provide related advantages.
摘要:
Method, system, and computer program product embodiments for, in a computing storage environment for destaging data from nonvolatile storage (NVS) to a storage unit, identifying working data on a stride basis by a processor device are provided. A multi-update bit is established for each of a plurality of strides in a modified cache, wherein the multi-update bit is adapted to indicate a corresponding stride is part of at least one track in a working set that refers to a group of frequently updated tracks. The plurality of strides are scanned based on a schedule to identify tracks for destaging. An operation to destage is performed on a selected track identified during the scanning, if the multi-update bit of a selected stride on the selected track is set to indicate the selected track is part of the working set and if the NVS is about 90% full or greater.
摘要:
An apparatus and method for copying data are disclosed. A data track to be replicated using a peer-to-peer remote copy (PPRC) operation is identified. The data track is encoded in a non-transitory computer readable medium disposed in a first data storage system. At a first time, a determination of whether the data track is stored in a data cache is made. At a second time, the data track is replicated to a non-transitory computer readable medium disposed in a second data storage system. The second time is later than the first time. If the data track was stored in the data cache at the first time, a cache manager is instructed to not demote the data track from the data cache. If the data track was not stored in the data cache at the first time, the cache manager is instructed that the data track may be demoted.