Administrator Guide

Repeat the process of check and modify until the batch migration plan passes the plan check. For example:
VPlexcli:/> batch-migrate check-plan --file migrate.txt
Checking migration plan file /temp/migration_plans/migrate.txt.
Plan-check passed.
Modifying a batch migration file
To modify a batch migration file, do one of the following:
About this task
● Use the batch-migrate create-plan command, specify the same filename, and use the --force option to overwrite
the old plan with the new one.
● Exit from the management server, and navigate to /var/log/VPlex/cli/.
Use a text editor (vi) to edit and save the file.
VPlexcli:/> exit
Connection closed by foreign host.
service@ManagementServer:~> cd /var/log/VPlex/cli/
service@ManagementServer:/var/log/VPlex/cli>
NOTE: To add comments to the migration plan file, add lines beginning with “/ “.
Starting a batch migration
About transfer-size
Transfer-size is the size of the region in cache used to service the migration. The area is globally locked, read at the source, and
written at the target.
Transfer-size can be as small 40 K, as large as 128 M, and must be a multiple of 4 K. The default recommended value is 128 K.
A larger transfer-size results in higher performance for the migration, but may negatively impact front-end I/O. This is especially
true for metro node Metro migrations.
A smaller transfer-size results in lower performance for the migration, but creates less impact on front-end I/O and response
times for hosts.
Set a large transfer-size for migrations when the priority is data protection or migration performance. Set a smaller transfer-size
for migrations when the priority is front-end storage response time.
Factors to consider when specifying the transfer-size:
● For metro node Metro configurations with narrow inter-cluster bandwidth, set the transfer size lower so the migration does
not impact inter-cluster I/O.
● The region specified by transfer-size is locked during migration. Host I/O to or from that region is held. Set a smaller
transfer-size during periods of high host I/O.
● When a region of data is transferred, a broadcast is sent to the system. Smaller transfer-size mean more broadcasts, slowing
the migration.
Use the batch-migrate start command to start the specified batch migration:
For example:
VPlexcli:/> batch-migrate start --file migrate.txt --transfer-size 2M
Started 4 of 4 migrations.
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Data migration