摘要:
A cascaded RDF system includes a local RDF site coupled to a source of data, a remote RDF site, and at least one intermediate RDF site, interposed between the local RDF site and the remote RDF site. Data written by the source of data to the local RDF site is propagated through the at least one intermediate RDF site to be stored at the remote RDF site. The source of data may be a host. There may be more than one intermediate RDF site. The cascaded RDF system may also include an additional remote RDF site, coupled to one of the at least one intermediate RDF site.
摘要:
Transferring data from a local storage device to a remote storage device includes providing, to a portion of the local storage device, data to be transferred from the local storage device to the remote storage device using a first mode that accesses an indicator of data being transferred, selecting a second mode for transferring data different from the first mode, where the second mode does not require the indicator, subdividing the portion of the local storage device into chunks, for each of the chunks, transferring the data, and, after all of the data from the chunks has been transferred, using the second mode for transferring data that is provided to the local storage device after selecting the second mode. Transferring data from a local storage device to a remote storage device may also include, prior to all of the data from the chunks being transferred, using a transition mode different from the first and second modes to transfer data that is provided to the local storage device after selecting the second mode, where the transition mode does not require the indicator.
摘要:
Described are techniques used in dynamically modifying RDF groups. A system call is issued by a host computer system to execute a remote system call on a first data storage system to create, remove, or modify an RDF group between the first data storage system and another data storage system that is remotely connected to the first data storage system in an RDF switched environment. As part of executing the remote system call, data is pushed from the first to the second data storage systems without having an established link between the data storage systems. Each data storage system performs processing to make the necessary modifications in all directors in accordance with the dynamic RDF group. A status indicating success or failure of the remote system call is returned to the host computer system.
摘要:
A diskless storage device includes a volatile memory and at least one director, coupled to the volatile memory, that receives data for the diskless storage device and provides the data to the volatile memory. The at least one director provides logical storage device functionality without using non-volatile memory. The logical storage device functionality may include addressing tracks, blocks, and cylinders of logical storage devices of the diskless storage device. The volatile memory may include a plurality of slots and where data is stored in the slots. Data may be stored in unused ones of the slots and/or slots marked for reuse.
摘要:
Reading data from a storage device includes presenting a read request to the storage device. In response to a more recent version of the data not being available on the storage device, the storage device requests the data from another storage device coupled to the storage device. In response to the more recent version of the data being available at the other storage device, the storage device obtains and copies the more recent version of the data prior to servicing the read request. The storage device services the read request by providing the data if the data is available. The storage device and the other storage device may be coupled using an RDF protocol.
摘要:
Described are techniques for evaluating data movement alternative. A set of criteria including capacity and performance limits is received. First processing is performed to evaluate a plurality of alternatives for use in data movement with respect to a set of logical devices having data stored on a set of physical storage devices. Each of the plurality of alternatives includes a different set of data movement criteria comprising capacity limits and a different set of performance limits. The set of physical storage devices includes at least a first physical device of one of a plurality of storage tiers and a second physical device of another one of the plurality of storage tier. One of the sets of performance limits is selected in accordance with the first processing.
摘要:
A networked data storage system includes data movement logic and a virtual machine for executing a data management processing plan which is generated by a facility outside the storage array based on statistical information associated with extent level activity metrics provided by the storage array. Dynamically updated and automatically generated data management processing plans are provided to the storage array in the form of units of compiled byte code which the storage array is able to verify and execute using a virtual machine. The virtual machine interfaces with the environment in which it is embedded in a carefully constrained manner, thereby preventing clearly undesirable operations.
摘要:
A method, computer program product, and computing system for identifying compressed content within a first cache system to a data array associated with the first cache system. Related content is located on the data array that is associated with the compressed content on the first cache system and it is determined whether the related content on the data array is compressible.
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:
Techniques are described for processing a data operation that writes first data to a data portion currently stored on first physical storage of a first storage tier of a data storage system, including storage tiers each having a different performance ranking relative to other storage tiers. Second physical storage is allocated from one of the storage tiers for storing the first data written to the data portion. This one storage tier is selected independent of the first storage tier. The first data is stored in a cache and destaged from the cache to the second physical storage. A single merged copy of data for the data portion is formed. Based on an activity level of the data portion, a target tier is selected for storing the single merged copy of data for the data portion.