Abstract: A processing device is configured to control delivery of input-output (IO) operations from a host device to a storage system over selected ones of a plurality of paths through a network, and to monitor response times for particular ones of the IO operations sent from the host device to the storage system. The processing device is further configured, responsive to at least a subset of the monitored response times being above a threshold over a time period, to generate an alert, to send the alert to an intermediary device coupled to the host device and the storage system, to receive from the intermediary device a throttling command generated in the intermediary device based at least in part on the alert, and responsive to receipt of the throttling command, to at least temporarily reduce a rate at which additional ones of the IO operations are sent from the host device to the storage system.

Abstract: An apparatus comprises at least one processing device that is configured to send write requests to a first storage system. The first storage system is configured to participate in a replication process in which data associated with the write requests is replicated from the first storage system to a second storage system that is separate from the first storage system. The at least one processing device is further configured to receive from the first storage system an indication of a write pressure condition arising in the second storage system and relating to replication of the data associated with the write requests from the first storage system to the second storage system, and to at least temporarily limit a manner in which additional write requests are sent to the first storage system responsive to the received indication of the write pressure condition arising in the second storage system.

Abstract: An apparatus comprises at least one processing device that includes a processor coupled to a memory. The processing device is configured to control delivery of input-output (IO) operations from a host device to at least one storage system over selected ones of a plurality of paths through a network, wherein the paths are associated with respective initiator-target pairs, the initiators being implemented on the host device and the targets being implemented on the storage system. The processing device is further configured to identify one or more of the plurality of paths that each exhibits at least a threshold amount of mismatch between a negotiated rate of its initiator and a negotiated rate of its target, and to modify path selection in the host device to at least temporarily avoid selecting the one or more identified paths. The processing device illustratively comprises at least a portion of the host device.

Abstract: An apparatus comprises at least one processing device that includes a processor coupled to a memory. The processing device is configured to control delivery of input-output (IO) operations from a host device to at least first and second storage systems over selected ones of a plurality of paths through a network, the first and second storage systems being arranged in an active-active configuration relative to one another. The processing device is further configured to identify one or more logical storage devices that are each accessible via at least first and second different ones of the paths to respective ones of the first and second storage systems, and to modify path selection for IO operations directed to the one or more identified logical storage devices relative to path selection for IO operations directed to one or more other logical storage devices. The processing device illustratively comprises at least a portion of the host device.

Abstract: An apparatus in one embodiment comprises a host device configured to communicate over a network with a storage system comprising a plurality of storage devices. The host device comprises a set of input-output queues and a multi-path input-output driver configured to select input-output operations from the set of input-output queues for delivery to the storage system over the network. The multi-path input-output driver is further configured to send a predetermined command to the storage system over each of a plurality of paths from the host device to the storage system, to monitor a response time for the predetermined command on each of the paths, and to detect a performance issue with at least a given one of the paths based at least in part on the monitored response time. The predetermined command illustratively comprises a Small Computer System Interface (SCSI) “immediate” command of a particular type, such as a Test Unit Ready (TUR) command.

Abstract: An apparatus comprises a processing device comprising a processor coupled to memory. The processing device is configured to obtain maintenance information comprising an indication that a port of a storage system is scheduled for a maintenance activity and to determine that a host device utilizes the port for communication with the storage system. The processing device is further configured to issue an alert to the host device. The alert is configured to cause the host device to set a path associated with the port to a standby mode. The standby mode is configured to inhibit input-output operations from being submitted to the storage system along the path.

Abstract: An apparatus comprises a host device configured to communicate over a network with source and target storage systems. The host device, in conjunction with migration of a logical storage device from the source storage system to the target storage system, is further configured to obtain from the target storage system watermark information characterizing progress of the migration of the logical storage device from the source storage system to the target storage system, and to determine whether a given input-output operation is to be sent to the source storage system or the target storage system based at least in part on the watermark information obtained from the target storage system. The watermark information illustratively identifies a particular logical address in the logical storage device, up to and including for which corresponding data has already been copied from the source storage system to the target storage system in conjunction with the migration.

Abstract: An apparatus comprises a host device configured to communicate over a network with source and target storage systems. The host device, in conjunction with migration of a logical storage device from the source storage system to the target storage system, is further configured to obtain from the target storage system watermark information characterizing progress of the migration of the logical storage device from the source storage system to the target storage system, and to determine whether a given input-output operation is to be sent to the source storage system or the target storage system based at least in part on the watermark information obtained from the target storage system. The watermark information illustratively identifies a particular logical address in the logical storage device, up to and including for which corresponding data has already been copied from the source storage system to the target storage system in conjunction with the migration.

Abstract: A host device comprises a processor coupled to a memory. The host device is configured to obtain from a storage system connectivity information characterizing one or more ports of the storage system, and to automatically establish connectivity of a particular type between the host device and one or more logical storage devices of the storage system based at least in part on the obtained connectivity information. For example, the host device can obtain the connectivity information directly from the storage system or via at least one intermediary device such as a management station. In some embodiments, the obtaining and automatically establishing are performed by at least one multi-path input-output driver of a multi-path layer of the host device. The connectivity of a particular type illustratively comprises Internet Small Computer System Interface (iSCSI) connectivity between the host device and the storage system, although other connectivity types can be supported.

Abstract: A host device configures a first plurality of block devices each corresponding to a path between the host device and a control device of a storage system. The host device submits an inquiry to the storage system using a given block device of the first plurality of block devices. The host device receives from the storage system an indication that the given block device corresponds to a data logical volume that has been provisioned for use by the host device and issues a command to remove the first plurality of block devices based at least in part on receiving the indication. The host device performs a scan of the plurality of paths and configures, based at least in part on the scan, a second plurality of block devices each corresponding to a path of the plurality of paths between the host device and the data logical volume.

Abstract: A host device comprises a processor coupled to a memory. The host device is configured to obtain from a storage system connectivity information characterizing one or more ports of the storage system, and to automatically establish connectivity of a particular type between the host device and one or more logical storage devices of the storage system based at least in part on the obtained connectivity information. For example, the host device can obtain the connectivity information directly from the storage system or via at least one intermediary device such as a management station. In some embodiments, the obtaining and automatically establishing are performed by at least one multi-path input-output driver of a multi-path layer of the host device. The connectivity of a particular type illustratively comprises Internet Small Computer System Interface (iSCSI) connectivity between the host device and the storage system, although other connectivity types can be supported.

Abstract: An apparatus comprises a processing device comprising a processor coupled to memory. The processing device is configured to obtain maintenance information comprising an indication that a port of a storage system is scheduled for a maintenance activity and to determine that a host device utilizes the port for communication with the storage system. The processing device is further configured to issue an alert to the host device. The alert is configured to cause the host device to set a path associated with the port to a standby mode. The standby mode is configured to inhibit input-output operations from being submitted to the storage system along the path.

Abstract: An apparatus comprises a host device configured to communicate over a network with first and second storage systems. The host device detects an association in at least one of the first and second storage systems between a source logical storage device of the first storage system and a target logical storage device of the second storage system, and responsive to the detected association, establishes a migration session in the host device for migration of the source logical storage device to the target logical storage device. The host device also obtains an indication from at least one of the first and second storage systems that a corresponding migration session has been activated in the first and second storage systems, and activates the previously-established migration session in the host device based at least in part on the obtained indication for migration of the source logical storage device to the target logical storage device.

Abstract: A storage entity of the data storage system may be visible to the host over a first path and a second path. The first path may operate in accordance with a first protocol and the second path may operate in accordance with a second different protocol. The storage entity may have a first protocol level personality and identity when presented to the host over the first path and a second protocol level personality and identity when presented to the host over the second path. A first native identifier associated of the storage entity on the first path and a second native identifier of the storage entity on the second path may be used to determine that the same storage entity is visible over the first and second paths even though the storage entity may have different protocol level identifiers on the first and second paths that operate using different protocols.

Abstract: An apparatus comprises a host device configured to communicate over a network with a storage system. The host device establishes a migration session in the host device for migration of a source logical storage device accessible utilizing a first access protocol to a target logical storage device accessible utilizing a second access protocol, and migrates the source logical storage device to the target logical storage device utilizing a multi-path layer of the host device. The multi-path layer maintains separate device identities for the respective source and target logical storage devices in conjunction with the migration session but presents a corresponding composite device having a single device identity to one or more applications executing on the host device. The multi-path layer translates one or more commands directed to the composite device in the first access protocol to one or more commands in the second access protocol.

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: A storage entity of the data storage system may be visible to the host over a first path and a second path. The first path may operate in accordance with a first protocol and the second path may operate in accordance with a second different protocol. The storage entity may have a first protocol level personality and identity when presented to the host over the first path and a second protocol level personality and identity when presented to the host over the second path. A first native identifier associated of the storage entity on the first path and a second native identifier of the storage entity on the second path may be used to determine that the same storage entity is visible over the first and second paths even though the storage entity may have different protocol level identifiers on the first and second paths that operate using different protocols.

Abstract: Transferring files directly from a storage system to a backup storage system includes determining identifiers for blocks on the storage system that correspond to files that are to be backed up, providing the identifiers for the blocks to the storage system, and the storage system pushing the blocks indicated by the identifiers directly from the storage system to the backup storage system. The identifiers may be logical block addresses. Determining the logical block addresses may vary according to a file system for files that are to be backed up. Determining the logical block address may include determining an inode value for each of the files that are to be backed up or may include determining a logical cluster number for each of the files that are to be backed up. The backup storage system may include a media server and a storage device.

Abstract: Combinations of host ports and storage ports (e.g., I-T pairs) on a storage network that are zoned but not masked may be determined, without accessing a switch or network administrator. Heartbeat communications (heartbeats) may be transmitted from host systems to each storage device of a storage system of which the host system is aware, along the one or more I/O paths of which the host is aware to the storage port of the I/O path. The storage devices may include one or more nominal devices defined for I-T pairs for which I/O connectivity has not been defined for any storage devices. The storage system may maintain a master heartbeat (heartbeat) table that may include a plurality of entries, each entry corresponding to a combination of a host port, storage port and storage device, and storing a time stamp value for a most recent heartbeat received for the combination.

Abstract: An apparatus comprises at least one processing device comprising a processor coupled to a memory. The processing device is configured to control performance of a migration process in which a source logical storage device of a first storage system is migrated to a target logical storage device of a second storage system. In conjunction with the migration process, the processing device is further configured to update a management header of the target logical storage device to include an identifier of the target logical storage device, to store an identifier of the source logical storage device, and responsive to a read of the management header of the target logical storage device, to return the identifier of the source logical storage device in place of the identifier of the target logical storage device. Other illustrative embodiments include methods and computer program products.