HP EVA-to-3PAR Online Import Migration Guide (T5494-96577)

Load restrictions on EVA Nearline drives
Due to the performance limitations of Nearline drives, care must be taken when migrating Vdisks
that are being serviced from a Nearline Diskgroup. The additional load placed on a Nearline
Diskgroup from the migration process can lead the hosts to experience higher than expected I/O
latencies. To reduce the likelihood of these high latencies causing unexpected failures, it is
recommended that the migration be carried out during a maintenance window or when the I/O
latencies prior to migration are at or below 30ms. To measure the latencies currently being
generated by the EVA, the following procedure can be used:
1. From the Command View server that is managing the array to be migrated.
Open HP P6000 command View Performance Data Collector.
2. Execute evaperf hps -cont 2 -dur 900 -ts2 -csv -sz array_WWNN > c:\
Array_loading.csv.
3. After the data collection completes, analyze the Read Latency (ms) and Write Latency
(ms)columns for the latencies observed during the data capture period.
4. Ensure that no host port latencies higher that 30ms are present in the data captured.
If the host port latencies are below 30ms, then you can proceed with the Online Import procedure
under this load level. If latencies higher than 30ms are observed, decrease the load on the EVA
array or perform the migration in an offline fashion.
Aborting a migration
A migration can be aborted in the following ways:
• A migration can be aborted by clicking Cancel at any time during the Add Migration Wizard.
• If the migration preparation process is complete, a migration can be aborted by clicking on
Abort in the Data Transfer column. You must click Completed to display the Abort button,
unless you are migrating unpresented virtual disks. In that case, the Abort button is displayed
immediately.
• Once a migration has started, it cannot be aborted.
Viewing migration status
NOTE: In the Storage Systems point of view, the HP EVA to 3PAR StoreServ Online Import aspect
tab is displayed only for storage systems that are eligible for migrations.
Viewing all migrations
1. In Command View, select the Settings point of view.
2. In the left navigation pane, select the HP EVA to 3PAR StoreServ Online Import instance.
The HP EVA to 3PAR StoreServ Online Import screen displays all the migrations in progress
or completed.
Viewing migrations for a storage system
1. In Command View, select the Storage Systems point of view.
2. In the left navigation pane, select the storage system.
3. In the content pane, select the HP EVA to 3PAR StoreServ Online Import aspect tab.
All migrations for the storage system are displayed.
Viewing migrations for hosts
1. In Command View, select the Storage Systems point of view.
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