摘要:
Described are techniques for determining preferred paths. A host requests first information from each of one or more ports of a data storage system. The first information includes preferred path information for a first device visible to the host through each port. The preferred path information includes one or more parameters used by said host to perform one or more mathematical calculations to determine a preferred path for transmitting to the data storage system a data operation directed to the first device. The first information is sent from each port to the host.
摘要:
Described are techniques for performing path selection. A data operation is received for a metadevice comprising a plurality of metadevice members. A first of the plurality of metadevice members is determined. The first member is the member to which the data operation is directed. In accordance with a load balancing technique for the first metadevice member, path selection is performed to select a first of a plurality of paths. The metadevice is accessible over each of the plurality of paths. The data operation is sent over the first path.
摘要:
Described are techniques for performing path selection. A data operation is received for a metadevice comprising a plurality of metadevice members. A first of the plurality of metadevice members is determined. The first member is the member to which the data operation is directed. In accordance with a load balancing technique for the first metadevice member, path selection is performed to select a first of a plurality of paths. The metadevice is accessible over each of the plurality of paths. The data operation is sent over the first path.
摘要:
Described are techniques for performing path selection. A data operation is received for a metadevice comprising a plurality of metadevice members. A first of the plurality of metadevice members is determined. The first member is the member to which the data operation is directed. In accordance with a load balancing technique for the first metadevice member, path selection is performed to select a first of a plurality of paths. The metadevice is accessible over each of the plurality of paths. The data operation is sent over the first path.
摘要:
Described are techniques for overriding an existing device reservation. Discovery processing is performed by a first data storage system to locate a specified device. The discovery processing includes determining whether there is a reservation conflict for said device of a second data storage system. If there is a reservation conflict for the device, a command is issued from the first data storage system to the second data storage system during said discovery processing to create an override for said reservation conflict. The override causes processing to be performed at a subsequent point in time so that an existing reservation associated with the reservation conflict is overridden in connection with performing a first process on said first data storage system.
摘要:
Example embodiments of the present invention provide for parallel replication of an IO received by a storage array. Such parallelism provide numerous benefits, including enqueuing the command phase of the write command at the storage array and the replication appliance in parallel, providing data still in memory (i.e., slot) and not destaged to disk, and providing data processing in parallel (e.g., validate checksum, validate data is good, validate internal data structures).
摘要:
Described are techniques for migrating data from a source device of a source data storage system to a target device of a target data storage system. The target data storage system is configured to operate in accordance with a spoofing mode and a pass-through mode. A first set of commands from the host are processed for the target device when in the pass-through mode and the spoofing mode with respect to the target device. Data is migrated from the source device to the target device. The target data storage system is configured to operate in an echo mode for the target device and processes a second set of commands from the host when in the echo mode for the target device using information stored in the cache from processing the first set of commands.
摘要:
A system creates a storage area network (SAN) centric storage virtualization layer in front of storage devices. The system allows data mobility and migration without disruption to the one or more host servers attached to the SAN. Specifically, the host servers are not disrupted when switching I/Os between physical and virtual storage, for example, by taking advantage of WWPN spoofing and Fibre Channel VSAN technology. The use of VSANs effectively allow multiple virtual directors and/or switches to be created within a physical director and/or switches, each with their own separate name server, thereby providing complete isolation from one another. The host-storage pathing information is unchanged as the original physical storage port's WWPNs are spoofed by the virtual storage port. The result is two identical WWPNs within the SAN which is normally disallowed; however, by separating the physical port WWPN into one VSAN and the virtual port WWPN into another, the restriction may be circumvented.
摘要:
Described is a distributed copying technique that may be used in migrating large amounts of data from one or more source devices to one or more destination devices. The data source is divided into partitions. As Fibre Channel adapters (FAs) become available, each of the FAs may copy a partition of the data. In connection with specifying paths used for the distributed copying technique, a preferred path selection (source port-target port mapping) may be made by executing code in a controlling data storage system to perform discovery processing. The preferred path selection is used for the duration of the distributed copying unless the preferred path is unable to transmit data. A target port of the preferred path may be randomly selected from all accessible target ports, and/or in accordance with a specified portion of the target ports. Preferred paths may also be specified using an API (application programming interface).
摘要:
Described is a distributed copying technique that may be used in migrating large amounts of data from one or more source devices to one or more destination devices. The data source is divided into partitions. As Fibre Channel adapters (FAs) become available, each of the FAs may copy a partition of the data. A copy indicator value indicates the last partition delegated to an FA for copying. The last FA to complete copying is responsible for ensuring completed copying of any other data partitions delegated to an FA which has died during migration of the other data partitions. In the event that the last FA dies prior to completing its processing, additional steps are performed by other remaining FAs to copy all data partitions not known to be successfully migrated.