Abstract: Example embodiments of the present invention provide a method, a system, and a computer program product for managing tasks in a system. The method comprises running a first task on a system, wherein the first task has a first priority of execution time and the execution of which first task locks a resource on the system, and running a second task on the system, wherein the second task has a second priority of execution time earlier than the first priority of execution time of the first task and the execution of which second task requires the resource on the system locked by the first task. The system then may promote the first task having the later first priority of execution time to a new priority of execution time at least as early as the second priority of execution time of the second task and resume execution of the first task having the later first priority of execution time.

Abstract: Example embodiments relate to a method, a system, and a computer program product for load balancing for port selection. The method includes determining a processing load for each storage port in a plurality of storage ports having variable processing power and calculating a delay characteristic for each storage port of the plurality of storage ports according to its processing load. A command then may be sent to a selected storage port of the plurality of storage ports according to the delay characteristics and a policy.

Abstract: Example embodiments of the present invention provide a method, a system, and a computer program product for managing tasks in a system. The method comprises running a first task on a system, wherein the first task has a first priority of execution time and the execution of which first task locks a resource on the system, and running a second task on the system, wherein the second task has a second priority of execution time earlier than the first priority of execution time of the first task and the execution of which second task requires the resource on the system locked by the first task. The system then may promote the first task having the later first priority of execution time to a new priority of execution time at least as early as the second priority of execution time of the second task and resume execution of the first task having the later first priority of execution time.

Abstract: Example embodiments of the present invention provide a method, a system, and a computer program product for managing tasks in a system. The method comprises running a first task on a system, wherein the first task has a first priority of execution time and the execution of which first task locks a resource on the system, and running a second task on the system, wherein the second task has a second priority of execution time earlier than the first priority of execution time of the first task and the execution of which second task requires the resource on the system locked by the first task. The system then may promote the first task having the later first priority of execution time to a new priority of execution time at least as early as the second priority of execution time of the second task and resume execution of the first task having the later first priority of execution time.

Abstract: Synchronization of data layouts and resource utilizations at one or more remote replica sites with the workload and data access statistics at the primary site allows for an efficient and effective workload support transfer in the event of site failover from a primary site to a remote site. Relevant data access information about workload being supported at the primary site is monitored and access pattern information is generated that provides relevant information about frequency and/or rate of access of data on the primary site. The access pattern information is generated and transmitted by a host and/application running on the host. The access pattern information is exported and imported to enable independent decisions to be made a remote site, storing replicated data from the primary site, on how best to utilize its available resources to match the performance requirements currently being supported by the primary site.

Abstract: Techniques and mechanisms for establishing and implementing performance objectives for an application based at least in part on a workload type of the application. A system includes a storage system on which an application imposes a workload by utilizing storage resources of the storage system, and a performance level has been associated with the application. A workload type is associated with the application based on the type of workload, and a performance objective is determined for the application based on the performance level and the workload type of the application. The storage resources are manipulated to achieve the performance objective.

Abstract: Example embodiments of the present invention relate to a method, an apparatus, and a computer program product for mirroring data in a data storage system across a first storage device having a first latency and a second storage device having a second latency. The method includes receiving an I/O at the data storage system and controlling the I/O to the first storage device having the first latency or the second storage device having the second latency according to properties of the I/O and properties of the first storage device having the first latency and the second storage device having the second latency.

Abstract: A Computer-executable method, system, and computer program product for managing tiers of data storage in a data storage environment using a data storage system, the Computer-executable method, system, and computer program product comprising a non-transitory computer readable medium encoded with computer-executable program code for using read signatures in replication, the code configured to enable the execution of initializing a data stack, updating a map of the data stack; and distributing the map of the data stack to a compute node.

Abstract: A storage cloud enabled platform includes storage nodes and application nodes which are the part of the same operating environment. The storage nodes and computation nodes are interconnected inside platform via an interface to provide improved response time and high bandwidth paths for storage applications. The computation nodes may include virtual or non-virtual machines. The interface may support various protocols depending on desired ease of use and response time. For example, a standardized protocol such as SCSI could be used for ease of use and data safety, or a direct data placement protocol could be used to help maximize response rate.

Abstract: A storage array uses both high endurance SSDs and low endurance SSDs for metadata paging. Wear cost values are calculated for each page of metadata in cache. The wear cost values are used to select pages for swapping out of the cache to the SSDs. The wear cost values may be calculated as a function of a first term that is indicative of whether the respective page of metadata will be written to high endurance or low endurance SSDs; a second term that is indicative of likelihood of data associated with the respective pages of metadata that will possibly be changed due to a write; and a third term that is indicative of age of the respective page of metadata in the cache since most recent use. The terms may be estimated and independently weighted. The portion of cache allocated for the metadata may be increased to avoid exceeding DWPD targets.

Abstract: Providing access to a host for requested data in a data storage array includes transferring the requested data from a cache memory of the data storage array to either the host or a host adaptor if the requested data is in the cache memory, transferring the requested data from a relatively slow non-volatile memory of the data storage array to the cache memory and subsequently transferring the requested data from the cache memory to either the host or the host adaptor if the requested data is in the relatively slow non-volatile memory and transferring the requested data simultaneously to the cache and to either the host and the host adaptor if the requested data is stored in relatively fast non-volatile memory. Data may be transferred directly from the relatively fast non-volatile memory to the host. The relatively fast non-volatile memory may be controlled by the host adaptor.

Abstract: Described embodiments provide systems and processes for performing a data replication process in a storage system. A current asynchronous replication cycle is initiated at a time-based interval based upon a replication policy of the storage system to replicate data from at least one source device to at least one target device. For the current asynchronous replication cycle, it is determined whether data stored on portions of the source device has changed from a previous asynchronous replication cycle. A new replica of the source device is generated if data stored on the source device has changed from the previous asynchronous replication cycle. The new replica is transferred to the target device. The current asynchronous replication cycle is completed and the replication policy of the storage system is satisfied without generating the new replica if data stored on the source device has not changed from the previous asynchronous replication cycle.

Abstract: Example embodiments of the present invention relate to a method, an apparatus, and a computer program product for directing I/Os for a chunk of data to a data storage system on which the chunk of data is stored. The host method includes receiving an I/O for a chunk of data, identifying to which data storage system the I/O should be sent to access the chunk of data, and sending the I/O for the chunk of data to the identified data storage system. Other example embodiments of the present invention relate to a method, an apparatus, and a computer program product for handling received I/Os during a migration of the chunk of data. The data storage system method includes migrating the chunk of data, queuing an I/O for the chunk of data received from a host during the migration, and rejecting the queued I/O as a result of the migration.

Abstract: A method system and program product for sending a hint from the server to the storage array, the hint relating access requests of data stored on the storage array, receiving the hint at the storage array, and updating information about the data stored on the storage array using the hint.

Abstract: Described embodiments provide methods and systems for tracking performance of a storage system including one or more system resources. One or more threads may be generated to operate the storage system. Each of the one or more threads may be associated with one of a plurality of tasks of the storage system. When an operating state of one of the one or more threads is changed, one or more performance counters of the storage system may be updated. A performance snapshot may be generated by capturing a state of the tasks associated with the threads and the performance counters.

Abstract: Exemplary methods for data migration from a first storage system to a second storage system include maintaining a database containing deduplication information associated with a plurality of remote target storage systems. In one embodiment, the methods include identifying a plurality of storage devices of the first storage system as candidates to be migrated to the second storage system based on access patterns of the storage devices at the first storage system, and selecting one or more storage devices from the identified candidates to be migrated to a second one of the plurality of remote target storage systems that is selected based on the deduplication information of the database. In one embodiment, the methods further include migrating one or more datasets stored at the selected one or more storage devices to the second storage system.

Abstract: Example embodiments of the present invention relate to a method, a system, and a computer program product for tiering metadata. The method includes selecting a consecutive range of addresses of a logical device having a parent data structure associated therewith maintaining a first set of hash values at a first granularity of the logical device. A second hash value then may be calculated over the consecutive range of addresses of the logical device at a second granularity of the logical device and inserted into a child data structure associated with the parent data structure. Entries in the parent data structure at the first granularity for the consecutive range of addresses then may be freed in favor of the second hash value at the second granularity for the consecutive range of addresses inserted into the child data structure, for storing hash values for other addresses of the logical device.

Abstract: Example embodiments of the present invention relate to a method, a system, and a computer program product for data storage tiering. The method includes maintaining data in a data storage system having a plurality of tiers, determining a subset of the data stored in a first, more-durable tier should be stored in a second, less-durable tier, and tiering the subset of the data from the first, more-durable tier to the second, less-durable tier.

Abstract: Identifying data for placement in a storage system having a plurality of storage classes includes subdividing the data into portions, for each of the portions, independently determining at least one score for a particular portion based on a metric corresponding to access of the particular portion, where the at least one score for the particular portion is independent of scores for other ones of the portions, and identifying sub-portions of data for placement in a particular storage class based on the at least one score of a portion of data corresponding to the sub-portions. The at least one score may be based on short term access statistics and long term access statistics. The access statistics may include read misses, writes, and prefetches.

Abstract: 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.