Abstract: Example implementations relate to determining, based on a system busy level, throughput of logical volumes. In example implementations, a system busy level may be increased in response to a determination that a latency goal associated with one of a plurality of logical volumes has not been met. A throughput for a subset of the plurality of logical volumes may be determined based on the system busy level.

Abstract: Examples disclosed herein relate to storage unit priority based on configuration information. For example, a processor may analyze configuration information associated with the storage units to create a priority order associated with the storage units. The configuration information associated with each storage unit may be standardized for comparison to the configuration information associated with the other storage units. The processor may perform an action related to the storage units according to the priority order.

Abstract: A method is provided for a destination storage system to handle SCSI-3 reservations. The method includes discovering a volume on a source storage system when the source storage system exports the volume to the destination storage system, exporting the volume to host computer systems, locally registering keys for first paths to the destination storage system, and registering with the source storage system the keys for second paths to the source storage system. When one of the host computer systems requests to reserve the volume, the method includes locally reserving the volume for paths to the destination storage system with registered keys and performing reservation forwarding to request the source storage system to reserve the volume for paths to the source storage system with registered keys.

Abstract: A failure at a first port of the controller node is detected, where the first port is initially assigned a first port identifier and is associated with a logical path through a communications fabric between the first port and a port at a host device. In response to detecting the failure, the first port identifier is assigned to a second port to cause the logical path to be associated with the second port. In response to detecting resolution of the failure, a probe identifier is assigned to the first port. Using the probe identifier, a health of network infrastructure between the first port and the host device is checked. In response to the checking, the first port identifier is assigned to the first port to cause failback of the logical path to the first port.

Abstract: Disclosed herein are techniques for managing the performance of a storage system. A subset of a plurality of storage units is associated with a rule that specifies a number of input and output transactions and a number of bits per time unit. The associations are adjusted in accordance with a performance policy and changes in the subset of the plurality of storage units.

Abstract: A method is provided for a destination storage system to join a storage area network with a source storage system. The method includes discovering a volume on the source storage system when the source storage system exports the volume to the destination storage system and exporting the volume to the host computer systems. When a command to reserve the volume for a host computer system is received, the method includes determining locally if the volume is already reserved. When the volume is not already reserved, the method includes reserving locally the volume for the host computer system and transmitting to the source storage system another command to reserve the volume for the destination storage system.

Abstract: A method to provide resiliency with a destination volume in a replication environment is disclosed. Data from a source volume, such as a primary volume or a secondary volume in a replication relationship, is migrated to the destination volume. A snapshot representing data on a source volume is generated. The replication relationship between the source volumes is broken, and a new relationship between a source volume and the destination volume is established. A delta of data between the snapshot and one of the volumes in the new relationship is generated. The delta is sent to the other of the volumes in the new relationship.

Abstract: Each node in a clustered array is the owner of a set of zero logical disks (LDs). Thinly-provisioned VVs (TPVVs) are partitioned so each is mapped to a group of zero LDs from different sets of zero LDs. When there is a change in ownership, the affected zero LDs are switched one at a time so only a group of the TPVVs is affected each time.

Abstract: Disclosed herein are a system, non-transitory computer readable medium and method for managing storage workloads. The performance of a storage unit is adjusted if the storage unit contributes to a nonconformity or violation of a performance policy.

Abstract: Optimization of a RAID volume is described. In an example, a method of optimizing a redundant array of independent disks (RAID) volume includes: identifying a RAID level used for a plurality of disks in the RAID volume; defining a relation among rebuild rate, scrub rate, and annualized data loss event rate (ADLER) for the RAID volume using constant values and the RAID level; selecting a value for the ADLER; applying a policy to the relation to choose a value for one of the rebuild rate or the scrub rate; and determining a value for the other of the rebuild rate or the scrub rate from the relation using the value of the rebuild rate or the scrub rate as determined from the policy.

Abstract: Optimization of a RAID volume is described. In an example, a method of optimizing a redundant array of independent disks (RAID) volume includes: identifying a RAID level used for a plurality of disks in the RAID volume; defining a relation among rebuild rate, scrub rate, and annualized data loss event rate (ADLER) for the RAID volume using constant values and the RAID level; selecting a value for the ADLER; applying a policy to the relation to choose a value for one of the rebuild rate or the scrub rate; and determining a value for the other of the rebuild rate or the scrub rate from the relation using the value of the rebuild rate or the scrub rate as determined from the policy.

Abstract: A method to provide resiliency with a destination volume in a replication environment is disclosed. Data from a source volume, such as a primary volume or a secondary volume in a replication relationship, is migrated to the destination volume. A snapshot representing data on a source volume is generated. The replication relationship between the source volumes is broken, and a new relationship between a source volume and the destination volume is established. A delta of data between the snapshot and one of the volumes in the new relationship is generated. The delta is sent to the other of the volumes in the new relationship.

Abstract: A method is provided for a destination storage system to handle SCSI-3 reservations. The method includes discovering a volume on a source storage system when the source storage system exports the volume to the destination storage system, exporting the volume to host computer systems, locally registering keys for first paths to the destination storage system, and registering with the source storage system the keys for second paths to the source storage system. When one of the host computer systems requests to reserve the volume, the method includes locally reserving the volume for paths to the destination storage system with registered keys and performing reservation forwarding to request the source storage system to reserve the volume for paths to the source storage system with registered keys.

Abstract: A method is provided for a destination storage system to join a storage area network with a source storage system. The method includes discovering a volume on the source storage system when the source storage system exports the volume to the destination storage system and exporting the volume to the host computer systems. When a command to reserve the volume for a host computer system is received, the method includes determining locally if the volume is already reserved. When the volume is not already reserved, the method includes reserving locally the volume for the host computer system and transmitting to the source storage system another command to reserve the volume for the destination storage system.

Abstract: Data de-duplication is done on a data set. The data de-duplication is done using a partial digest table. Some digests are selective removed from the partial digest table when a pre-determined condition occurs.

Abstract: A method for migrating data in a storage system includes generating a first set of logical disks (LDs), the LDs being mapped to physical storage space in the storage system, generating a temporary virtual volume (VV) mapped to the first set of LDs, generating a second set of LDs mapped to the temporary VV, and migrating data between the second set of LDs and a third set of LDs.

Abstract: Each node in a clustered array is the owner of a set of zero logical disks (LDs). Thinly-provisioned VVs (TPVVs) are partitioned so each is mapped to a group of zero LDs from different sets of zero LDs. When there is a change in ownership, the affected zero LDs are switched one at a time so only a group of the TPVVs is affected each time.

Abstract: One embodiment of the present invention provides a distributed file system that is able to use direct connections between clients and disks to perform file system operations. Upon receiving a request at a client to access a file, the client performs a lookup in a local cache to determine what physical disk blocks are associated with the request. If the lookup cannot be satisfied from the local cache, the client forwards the request to a server. In response to the forwarded request, the client receives a block map for the file from the server. This block map includes location information specifying physical disk blocks containing the file. The client uses this block map to determine which physical disk blocks are involved in the request and then accesses the file directly from the disk without going through the server.

Abstract: One embodiment of the present invention provides a system that facilitates assigning an identifier to a device within a distributed computing system, wherein the identifier is unique across the distributed computing system. The system operates by detecting the presence of the device within a local computer system within the distributed computing system. If an identifier has not been assigned to the device, the system assigns an identifier to the device by, attempting to retrieve the identifier from a local pool of device identifiers within the local computer system. If the local pool is empty, the system retrieves at least one additional identifier for the local pool from a global allocator for device identifiers located within the distributed computing system. Next, the system assigns the retrieved identifier to the device so that the identifier can be used to reference the device.

Abstract: One embodiment of the present invention provides a distributed file system that is able to use direct connections between clients and disks to perform file system operations. Upon receiving a request at a client to access a file, the client performs a lookup in a local cache to determine what physical disk blocks are associated with the request. If the lookup cannot be satisfied from the local cache, the client forwards the request to a server. In response to the forwarded request, the client receives a block map for the file from the server. This block map includes location information specifying physical disk blocks containing the file. The client uses this block map to determine which physical disk blocks are involved in the request and then accesses the file directly from the disk without going through the server.