摘要:
Described is a distributed copying technique that may be used in migrating large amounts of data from one or more source devices to one or more destination devices. The data source is divided into partitions. As Fibre Channel adapters (FAs) become available, each of the FAs may copy a partition of the data. In connection with specifying paths used for the distributed copying technique, a preferred path selection (source port-target port mapping) may be made by executing code in a controlling data storage system to perform discovery processing. The preferred path selection is used for the duration of the distributed copying unless the preferred path is unable to transmit data. A target port of the preferred path may be randomly selected from all accessible target ports, and/or in accordance with a specified portion of the target ports. Preferred paths may also be specified using an API (application programming interface).
摘要:
Described are techniques for use with online data copying or migration. Data is pushed from a source to a target device while one or both of the source and target devices are available for use by one or more host systems. The host systems may perform I/O operations to the source and/or target devices while the data migration is ongoing if a copy session is defined on the data storage system(s) of the source and/or target devices. A copying operation performs data migration from the source to the target device. A migration vector is used to indicate which portions of the source have been migrated. A change vector may be associated with each of the source and/or target devices to indicate portions that have been modified in order to perform a differential copy operation.
摘要:
Described are techniques for use with an error handling policy for a data storage system. Error handling criteria may be specified for controlling behavior of the data storage system upon the occurrence of an internal processing error occurring when performing an ancillary task associated with a data operation received by the data storage system. The error handling criteria may include a threshold counter value, and one or more of: a device, a specific device location or address, and a host. An error may be conditionally returned to the host upon the occurrence of an internal processing error in accordance with the error handling criteria.
摘要:
Described is a distributed copying technique that may be used in migrating large amounts of data from one or more source devices to one or more destination devices. The data source is divided into partitions. As Fibre Channel adapters (FAs) become available, each of the FAs may copy a partition of the data. In connection with specifying paths used for the distributed copying technique, a preferred path selection (source port-target port mapping) may be made by executing code in a controlling data storage system to perform discovery processing. The preferred path selection is used for the duration of the distributed copying unless the preferred path is unable to transmit data. A target port of the preferred path may be randomly selected from all accessible target ports, and/or in accordance with a specified portion of the target ports. Preferred paths may also be specified using an API (application programming interface).
摘要:
Described is a distributed copying technique that may be used in migrating large amounts of data from one or more source devices to one or more destination devices. The data source is divided into partitions. As Fibre Channel adapters (FAs) become available, each of the FAs may copy a partition of the data. A copy indicator value indicates the last partition delegated to an FA for copying. The last FA to complete copying is responsible for ensuring completed copying of any other data partitions delegated to an FA which has died during migration of the other data partitions. In the event that the last FA dies prior to completing its processing, additional steps are performed by other remaining FAs to copy all data partitions not known to be successfully migrated.
摘要:
Described are techniques for allocating resources. Two consumer processes using two resources are provided. A first threshold of a first of the resources for a first of said two consumer processes is provided. A second threshold of a second of said resources for said first consumer process is provided. Consumption information is received regarding actual consumption of the two resources by the first consumer process. Execution of the first consumer process is scheduled in accordance with the first and the second thresholds and the consumption information.
摘要:
A technique migrates data from a source array to a target array while preserving SCSI reservation compliance. The technique involves providing an active-to-passive instruction to the source array while a first SCSI reservation enables hosts to access data on the source array using MPIO software. The active-to-passive instruction directs the source array to transition devices from active mode to passive mode and, upon receipt of a next SCSI instruction, output an indicator indicating that the first SCSI reservation has been cleared. The technique further involves transitioning devices of the target array from passive mode to active mode and beginning a data transfer operation which transfers data from the source array to the target array. The technique further involves automatically effectuating formation of a second SCSI reservation in place of the first SCSI reservation, the second SCSI reservation providing host access to the data on the target array using MPIO software.
摘要:
Described are techniques for overriding an existing device reservation. Discovery processing is performed by a first data storage system to locate a specified device. The discovery processing includes determining whether there is a reservation conflict for said device of a second data storage system. If there is a reservation conflict for the device, a command is issued from the first data storage system to the second data storage system during said discovery processing to create an override for said reservation conflict. The override causes processing to be performed at a subsequent point in time so that an existing reservation associated with the reservation conflict is overridden in connection with performing a first process on said first data storage system.
摘要:
Example embodiments of the present invention provide for parallel replication of an IO received by a storage array. Such parallelism provide numerous benefits, including enqueuing the command phase of the write command at the storage array and the replication appliance in parallel, providing data still in memory (i.e., slot) and not destaged to disk, and providing data processing in parallel (e.g., validate checksum, validate data is good, validate internal data structures).
摘要:
Described are techniques for determining preferred paths. A host requests first information from each of one or more ports of a data storage system. The first information includes preferred path information for a first device visible to the host through each port. The preferred path information includes one or more parameters used by said host to perform one or more mathematical calculations to determine a preferred path for transmitting to the data storage system a data operation directed to the first device. The first information is sent from each port to the host.