symcli parallel ops

Performing SRDF Control Operations in Parallel

Some SRDF operations require a considerable amount of time to complete, especially establish operations that need to mark and merge track tables between the R1 and R2 devices. If an application such as batch replication to copy data warehouse loads requires establishing device groups across multiple Symmetrix arrays, doing so sequentially can take a considerable amount of time.

SYMCLI provides a configuration database on your host for SYMAPI access, which by default is set to EXCLUSIVE access to prevent the database from being changed while an operation is in progress. Under this access setting, one establish operation must complete before another begins.

However, if you know that there are no Symmetrix configuration changes currently being made to your host’s SYMAPI database, you can set access to the database to PARALLEL. With parallel access set, SYMCLI can process multiple SRDF operations such as symrdf establish simultaneously.

For example, if you need to establish SRDF pairs on three Symmetrix arrays, you can build a device group for each Symmetrix array, set the SYMCLI_CTL_ACCESS environment variable to PARALLEL, and issue three symrdf establish commands simultaneously:
Export SYMCLI_CTL_ACCESS=PARALLEL
symrdf -g group1 establish -noprompt &
symrdf -g group2 establish -noprompt &
symrdf -g group3 establish -noprompt &
wait


Beginning with the SRDF component of Solutions Enabler version 5.2 running on Symmetrix arrays using Enginuity version 5667, parallel processing is controlled at the device level rather than at the RDF group level. You can perform up to 64 parallel processing operations on different devices but no more than one operation on any one device at a time. Beginning with Enginuity version 5669, you can perform unlimited parallel processing operations on different devices. Moreover, these operations can span RDF groups.