Abstract: A technique provides transitioning from an original device to a new device within a data storage array. The technique involves initiating a copying activity within the data storage array, the copying activity copying data from the original device to the new device. The technique further involves, while the data is being copied from the original device to the new device, routing write requests that target logical storage which is currently supported by the original device to both the original device and the new device. The technique further involves, after the data has been copied from the original device to the new device, performing a configuration change which routes I/O requests that target the logical storage to the new device rather than the original device.

Abstract: Host computers running applications that store data on a block-based storage system such as a SAN provide hints that differentiate IO data based on which application generated the IO. The hints may include tags that are associated with IO commands sent to the block-based storage system. Each host application is associated with a unique identifier that is placed in the tag. Application name-to-identifier mappings may be sent from the hosts to the block-based storage system. Per-identifier/application deduplication statistics are maintained by the block-based storage system and shared with other block-based storage system. Deduplication is disabled or de-emphasized for IO data generated by applications with statistically low deduplication ratios.

Abstract: A host device is configured to obtain a default timeout value of the host device for the submission of an input-output (IO) operation to a storage system and to determine a first timeout value that is less than the default timeout value. The host device is further configured to submit the IO operation to the storage system along a first path using the first timeout value and to determine that the submission of the IO operation along the first path has timed out. The host device is further configured to determine a second timeout value that is greater than the first timeout value and to submit the IO operation to the storage system along a second path using the second timeout value.

Abstract: A technique provides transitioning from an original device to a new device within a data storage array. The technique involves initiating a copying activity within the data storage array, the copying activity copying data from the original device to the new device. The technique further involves, while the data is being copied from the original device to the new device, routing write requests that target logical storage which is currently supported by the original device to both the original device and the new device. The technique further involves, after the data has been copied from the original device to the new device, performing a configuration change which routes I/O requests that target the logical storage to the new device rather than the original device.

Abstract: An apparatus comprises a host device comprising at least one processor coupled to memory. The host device is configured to communicate over a network with a storage system comprising a plurality of storage devices. The host device is further configured to identify a logical volume identifier corresponding to a given logical volume of the storage system and to submit a message comprising an indication of the logical volume identifier to a messaging system. The host device is further configured to obtain, from the messaging system, an indication of a pseudo name corresponding to the logical volume identifier and to assign the obtained pseudo name to a multipath device corresponding to the given logical volume, the multipath device comprising a plurality of paths between the host device and the given logical volume.

Abstract: An apparatus in one embodiment comprises a host device configured to communicate over a network with a storage system. The host device comprises a plurality of nodes each comprising a plurality of processing devices and at least one communication adapter. The host device further comprises a multi-path input-output (MPIO) driver that is configured to obtain an input-output (IO) operation that targets a given logical volume and to identify a source node for the IO operation. The MPIO driver identifies a plurality of paths between the source node and the given logical volume via the communication adapters of the plurality of nodes and determines locality information for each identified path. The MPIO driver is further configured to select a target path from the identified paths based at least in part on the determined locality information and to deliver the obtained IO operation to the given logical volume via the selected target path.

Abstract: An apparatus in one embodiment comprises a host device that includes a set of input-output (IO) queues and a current multi-path input-output (MPIO) driver configured to select IO operations from the set of IO queues for delivery to the storage system. The current MPIO driver groups a plurality of paths from the host device to a logical volume of the storage system into a current multi-path logical device. The host device installs a target MPIO driver and migrates control of the multi-path logical device to the target MPIO driver from the current MPIO driver where the migration comprises generating a duplicate multi-path logical device for the target multi-path input-output driver, adding a new path to the current multi-path logical device that routes input-output operations to the duplicate multi-path logical device, and removing one or more paths of the current multi-path logical device other than the added new path.

Abstract: A host device comprises a plurality of communication adapters and is configured to communicate with a storage system. Each communication adapter comprises a plurality of input-output (IO) submission queues each having a submission queue priority class. A multi-path input-output (MPIO) driver is configured to deliver IO operations to the storage system over the network. The MPIO driver obtains an IO operation that targets a given logical volume of the storage system and determines a process tag value associated with the obtained IO operation. A mapping between the determined process tag value and a given submission queue priority class is determined and IO submission queues are identified as having the given submission queue priority class based at least in part on the mapping. A target IO submission queue is selected from the identified IO submission queues and the IO operation is dispatched to the selected target IO submission queue.

Abstract: An apparatus in one embodiment comprises a host device that is configured to communicate over a network with at least one storage system comprising a source logical storage volume and a target logical storage volume. Responsive to a reboot of the host device during a migration of a plurality of chunks of data from the source logical storage volume to the target logical storage volume, the host device is configured to determine, based at least in part on an entry of a copy migration journal, the entry corresponding to a given chunk of the plurality of chunks, that the migration of the given chunk was in progress prior to the reboot. Responsive to determining that the migration of the given chunk was in progress prior to the reboot, the host device is configured to resume the migration of the plurality of chunks from the given chunk.

Abstract: An apparatus comprises a host device configured to communicate over a network with a storage system. The host device comprises a plurality of communication adapters, each of which comprises a corresponding plurality of input-output (IO) submission queues, and a multi-path input-output (MPIO) driver configured to obtain an IO operation that targets a given logical volume of the storage system and to identify a plurality of paths between the host device and the given logical volume. Each identified path comprises a communication adapter and a corresponding IO submission queue of that communication adapter. An IO load weight and a queue depth weight are determined for each identified path. An adaptive weight for each identified path is determined as a function of the determined IO load weight and the determined queue depth weight for that identified path and a target path is selected from the identified paths based at least in part on the determined adaptive weights.

Abstract: An apparatus in one embodiment comprises a first host device comprising a processor coupled to a memory. The first host device is configured to assign to additional host devices different portions of a source logical unit designated for migration to a target logical unit. In conjunction with migration of the assigned portions of the source logical unit to the target logical unit by the additional host devices, the first host device is configured to receive from the additional host devices respective sets of information each characterizing one or more writes directed to the corresponding assigned portion during the migration. The first host device is further configured to update the target logical unit based at least in part on the received sets of information. In some embodiments, the first host device is configured to assign to itself a portion of the source logical unit designated for migration to the target logical unit.

Abstract: An apparatus in one embodiment comprises a host device configured to communicate over a network with a storage system. The host device comprises a plurality of nodes each comprising a plurality of processing devices and at least one communication adapter. The host device further comprises a multi-path input-output (MPIO) driver that is configured to obtain an input-output (IO) operation that targets a given logical volume and to identify a source node for the IO operation. The MPIO driver identifies a plurality of paths between the source node and the given logical volume via the communication adapters of the plurality of nodes and determines locality information for each identified path. The MPIO driver is further configured to select a target path from the identified paths based at least in part on the determined locality information and to deliver the obtained IO operation to the given logical volume via the selected target path.

Abstract: A host device comprises a current multi-path input-output (MPIO) driver that is configured to group paths from the host device to a source logical volume into a source multi-path logical device. A source multi-path logical device for a target MPIO driver is generated that has the same group of paths as the source multi-path logical device of the current MPIO driver. The source multi-path logical device of the target MPIO driver is added as a path in the source multi-path logical device of the current MPIO driver and the other paths are removed. A target multi-path logical device for the target MPIO driver is generated that groups paths from the host device to a target logical volume into the target multi-path logical device. Data from the source logical volume to the target logical volume is migrated based at least in part on the source and target multi-path logical devices of the target MPIO driver.

Abstract: An apparatus in one embodiment comprises a host device that includes a set of input-output (IO) queues and a current multi-path input-output (MPIO) driver configured to select IO operations from the set of IO queues for delivery to the storage system. The current MPIO driver is configured to group a plurality of paths from the host device to a logical unit number of the storage system into a multi-path logical device. The host device is configured to install a target MPIO driver and to migrate control of the multi-path logical device to the target MPIO driver from the current MPIO driver where the migration comprises transferring IO entry points of the multi-path logical device from the current MPIO driver to the target MPIO driver. The host device is configured to deliver IO operations selected by the target MPIO driver to the storage system using the multi-path logical device.

Abstract: An apparatus in one embodiment comprises a host device that includes a set of input-output (IO) queues and a current multi-path input-output (MPIO) driver configured to select IO operations from the set of IO queues for delivery to the storage system. The current MPIO driver groups a plurality of paths from the host device to a logical volume of the storage system into a current multi-path logical device. The host device installs a target MPIO driver and migrates control of the multi-path logical device to the target MPIO driver from the current MPIO driver where the migration comprises generating a duplicate multi-path logical device for the target multi-path input-output driver, adding a new path to the current multi-path logical device that routes input-output operations to the duplicate multi-path logical device, and removing one or more paths of the current multi-path logical device other than the added new path.

Abstract: An apparatus in one embodiment comprises a first host device comprising a processor coupled to a memory. The first host device is configured to assign to additional host devices different portions of a source logical unit designated for migration to a target logical unit. In conjunction with migration of the assigned portions of the source logical unit to the target logical unit by the additional host devices, the first host device is configured to receive from the additional host devices respective sets of information each characterizing one or more writes directed to the corresponding assigned portion during the migration. The first host device is further configured to update the target logical unit based at least in part on the received sets of information.

Abstract: An apparatus in one embodiment comprises a host device configured to communicate with a storage system. Responsive to an instruction to migrate data from a source volume to a destination volume, the host device replaces an input-output entry function of a source pathing device associated with the source volume with a migration input-output entry function that is configured, in response to receiving an input-output operation, to call an input-output entry function of a destination pathing device associated with the destination volume and to call the input-output entry function of the source pathing device. Responsive to an indication that a migration of data has completed, the host device replaces the migration input-output entry function with a post-migration input-output entry function. The post-migration input-output function is configured to call the input-output entry function of the destination pathing device in response to receiving an input-output operation.

Abstract: I/O storage processing behavior is controlled on a storage system based on an application instance of an I/O request. I/O storage processing behavior may be associated with application instances on a host by creating a table or other data structure that assigns identifiers to each application instance and specifies associate behavior(s) with the application instance. The table may associate behavior to application instances based on logical groupings of application instances, which may be based on existing defined groups or other logical entities, for example, a container or VM. A host may communicate the table to a storage system, and the storage system may store information from the table. An I/O request on the host may be tagged with an ID from the table, and sent to the storage system, which controls the I/O storage processing of the I/O request according to the tagged ID.

Abstract: An apparatus in one embodiment comprises a host device that includes a set of input-output (IO) queues and a current multi-path input-output (MPIO) driver configured to select IO operations from the set of IO queues for delivery to the storage system. The current MPIO driver is configured to group a plurality of paths from the host device to a logical unit number of the storage system into a multi-path logical device. The host device is configured to install a target MPIO driver and to migrate control of the multi-path logical device to the target MPIO driver from the current MPIO driver where the migration comprises transferring IO entry points of the multi-path logical device from the current MPIO driver to the target MPIO driver. The host device is configured to deliver IO operations selected by the target MPIO driver to the storage system using the multi-path logical device.

Abstract: I/O storage processing behavior is controlled on a storage system based on an application instance of an I/O request. I/O storage processing behavior may be associated with application instances on a host by creating a table or other data structure that assigns identifiers to each application instance and specifies associate behavior(s) with the application instance. The table may associate behavior to application instances based on logical groupings of application instances, which may be based on existing defined groups or other logical entities, for example, a container or VM. A host may communicate the table to a storage system, and the storage system may store information from the table. An I/O request on the host may be tagged with an ID from the table, and sent to the storage system, which controls the I/O storage processing of the I/O request according to the tagged ID.