Emc IP Holding Company LLC

Dell Products Inc.

Venkatesh Doddamane Nagaraj

Kurumurthy Gokam

Peniel Charles

Ashwin Ramkrishna Tidke

Amit Pundalik Anchi

Saurabh Tripathi

Poonam Garg

Hanish Kandangattu Hariharan

An apparatus in one embodiment comprises at least one processing device configured to store a mapping for each of a plurality of logical storage devices of a storage system, the mapping for a given one of the logical storage devices assigning different ranges of logical block addresses of that logical storage device to respective different cache entities of the storage system. The at least one processing device is further configured to receive at least one mapping-related communication from at least one of first and second host devices that have shared access to the given logical storage device, to modify the stored mapping for the given logical storage device based at least in part on the at least one received mapping-related communication, and to send at least one mapping-related communication to at least one of the first and second host devices based at least in part on the modified stored mapping.

Synchronized mapping for cache-aware load balancing across multiple host devices

An apparatus comprises a processing device configured to identify a plurality of data portions from a source storage volume to be copied to a target storage volume, and to analyze performance of respective ones of a plurality of host devices in connection with at least one copying operation. Respective ones of the plurality of host devices are assigned to perform copying of respective subsets of the plurality of data portions to the target storage volume based, at least in part, on the analysis.

Load sharing of copy workloads in device clusters

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.

Fast multipath failover

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.

Storage system with submission queue selection utilizing application and submission queue priority

An apparatus comprises a host device comprising a processor coupled to memory. The host device is configured to obtain a network congestion notification from a portion of a network that is utilized by the host device for submitting IO operations to a storage system. The network congestion notification comprises an indication that the portion of the network is experiencing network congestion. The host device is further configured to identify a first path of a plurality of paths as a path that utilizes the portion of the network and to adjust a dispatch weight of the first path based at least in part on the network congestion notification. The host device is further configured to submit an IO operation to the storage system along a second path instead of the first path based at least in part on the adjusted dispatch weight of the first path.

Congestion aware multipathing based on network congestion notifications

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.

Adaptive load balancing in storage system having multiple input-output submission queues

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.

Migration resumption using journals

A host computer dispatches storage I/O operations to a storage array by, in an I/O dispatch context, (i) identifying an I-T-L nexus based on a minimum-weight I-T nexus and a logical device of a storage I/O operation, (ii) dispatching the I/O on the identified I-T-L nexus, and (iii) updating a dispatch weight for the minimum-weight I-T nexus and logical device. In an I/O completion context, a completion weight is updated for an I-T nexus and logical device of a completed I/O. A background process is performed regularly for selecting the minimum-weight I-T nexus, including (a) for each I-T nexus, calculating a current weight value as a sum of difference values for all logical devices, each being the difference between the dispatch weight and the completion weight for the I-T nexus and logical device, and (b) selecting the I-T nexus having a minimum current weight value as the minimum-weight I-T nexus.

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Bengaluru, India

Venkatesh Doddamane Nagaraj