Abstract: Trust may be maintained between a storage system and a host system by the host system validating its identity to the storage system. The storage system may instruct the host system to validate itself by setting a validation flag on the storage system. The host system may be configured to determine whether the validation flag is set. If the host system determines that the validation flag is set, the host system then may read a test string from the storage system. The host system may encrypt the test string using a private key, and send the encrypted test string to the storage system. The storage system may decrypt the encrypted string using a public key it previously received from the host system. The decrypted test string then may be compared against the original test string generated by the storage system.

Abstract: A processing node of a storage system may determine that a host system is implementing a cache-slot aware, round-robin IO distribution algorithm (CA-RR). The processing node may be configured to determine when a sufficient number of sequential IOs will be received to consume a cache slot of the a processing node. If the processing node knows that the host system is implementing CA-RR, then, in response to determining the sufficient number, the processing node may send a communication informing the next processing node about the sequential cache slot hit. If the sequential IO operation(s) are read operation(s), the next processing node may prefetch at least a cache-slot worth of next consecutive data portions. If the sequential IO operation(s) are write operation(s), then the next processing node may request allocation of one or more local cache slots for the forthcoming sequential write operations.

Abstract: Embodiments are described for dynamically allocating and reallocating system resources between production work tasks and administrative tasks using policies. A resource monitor continuously monitors all resources in a computing system, and whether the resources are used for production work or administrative tasks. A policy can define resources needed to execute an administrative task and conditions which can be used to determine whether or not the administrative command is allocated the resources, even at the expense of a negative impact to production work.

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 distributed cache is managed. In some embodiments, only a subset of a plurality of processing nodes may be designated as cache managers that manage the cache access history of a logical area, including having an exclusive right to control the eviction of data from cache objects of the logical area. In such embodiments, all of the processing nodes may collect cache access information, and communicate the cache access information to the cache managers. Some of the processing nodes that are not cache managers may collect cache access information from a plurality of the other non-cache managers. Each such processing node may combine this communicated cache access information with the cache access information of the processing node itself, sort the combined information per cache manager, and send the resulting sorted cache access information to the respective cache managers. The processing nodes may be arranged in a cache management hierarchy.

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: Memory of a storage system is made available (i.e., exposed) for use as host memory of a host, for example, as an extension of the main memory of the host. The host may be directly connected to an internal fabric of the data storage system. Portions of the storage system memory (SSM) may be allocated for use as host memory, and this may be communicated to the host system. The host OS and applications executing thereon then may make use of the SSM as if it were memory of the host system, for example, as second-tier persistent memory. The amount of SSM made available may be dynamically increased and decreased. The SSM may be accessed by the host system as memory; i.e., in accordance with memory-based instructions, for example, using remote direct memory access instructions. The SSM may be write protected using mirroring, vaulting and other techniques.

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 first host device establishes connectivity to a logical storage device of a storage system. The first host device obtains from the storage system host connectivity information identifying at least a second host device that has also established connectivity to the logical storage device, caches one or more extents of the logical storage device in a memory of the first host device, and maintains local cache metadata in the first host device regarding the one or more extents of the logical storage device cached in the memory of the first host device. In conjunction with processing of a write operation of the first host device involving at least one of the one or more cached extents of the logical storage device, the first host device invalidates corresponding entries in the local cache metadata of the first host device and in local cache metadata maintained in the second host device.

Abstract: Application discovery from access patterns is disclosed. Access histories from multiple servers are collected and stored at a warehouse, which me part of a data protection system. A time series analysis is performed on the access history to identify consistency groups and applications from the perspective of devices and storage arrays. Data protection operations such as backup operations can then be performed on the basis of devices or storage in storage arrays or other arrangements that pertain to specific consistency groups or to specific applications.

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: 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: 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 at least one processing device comprising a processor coupled to a memory. The at least one processing device is configured to receive, via a multi-path layer of at least one host device, at least one indication of a predicted distribution of input-output operations directed from the at least one host device to a storage system for a given time interval. The at least one processing device is also configured to determine a cache memory configuration for a cache memory associated with the storage system based at least in part on the at least one indication of the predicted distribution of input-output operations for the given time interval. The at least one processing device is further configured to provision the cache memory with the determined cache memory configuration for the given time interval.

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: Techniques for protecting information may include: exposing a logical device of a data storage system to a host, wherein the logical device has an attribute identifying the logical device as a stealth device having accessibility controlled by the data storage system based on commands issued over a control path, wherein the logical device has a mode indicating whether the logical device is accessible to the host; sending, from the host to the data storage system, a write command that writes first data on the logical device when the mode indicates the logical device is accessible to the host; and subsequent to said sending, issuing a command over the control path to the data storage system, wherein the command sets the mode of the logical device to inaccessible indicating the logical device is not accessible to the host.

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.