HP StorageWorks XP Remote Web Console Software - Manual (Page 23)

Auto LUN XP user guide for the XP12000/XP10000 23
Progress value
If a volumes with heavy and light workloads are migrated together, the migration might not complete (even
though the progress value indicates 100%). If this happens perform one of the following tasks.
• Reduce the workloads between hosts and the disk array and complete the migration.
• Stop the migration for the volume with heavy workloads, migrate the other volume, and then retry the
migration which has been stopped.
Effects on other XP products
When the workloads for update I/Os between hosts and the disk array are heavy, longer time will be
required to complete the volume migration because the copy of differential data is repeatedly executed.
Longer copying times may be required for other XP products when this copy of differential data is
executed. These XP products include: Auto LUN XP, Business Copy XP, ShadowImage for z/OS®,
Compatible Mirroring for IBM® FlashCopy®, and Flex Copy XP.
See
Figure 8 for the amount of affected copying time. The copying time of other XP products depends on
the number of pairs set to the XP product, however, the copying time may be increased up to twice.
Maintenance
Do not perform Auto LUN XP migration operations during disk array maintenance activities (for example,
cache or drive installation, replacement, de-installation, or replacement of the microprogram).
Auto migration parameters
Auto migration parameters are initialized when the disk array configuration is changed (for example, when
new drives or LDEVs are installed). Parameters include disk usage limit and migration time. After a change
is made to the subsystem configuration, you must specify auto migration parameters again.
Powering off disk arrays
To turn the power off at the disk array, ensure that volume migration is finished. If migration is not finished,
HP strongly recommends that you do not turn off the power until the migration is finished.
If you turn the power off while migration is in progress, data migration stops and some of the data are not
migrated. If you turn the power on later, Auto LUN XP resumes data migration. If data remains in shared
memory, which is volatile memory, Auto LUN XP attempts to copy only data that have not been migrated to
the migration destination. However, if data is lost from shared memory, Auto LUN XP attempts to copy all
data to the migration destination; therefore, the copy operation takes more time. Auto LUN XP attempts to
Table 8 The estimated delay in the copying speed
Capacity of Migrated Volume (MB) Estimated delay in the copying
speed (in minutes)
0 - 1,000 4
1,001 - 5,000 18
5,001 - 10,000 37
10,001 - 50,000 186
50,001 - 100,000 372
100,001 - 500,000 1860
500,001 - 1,000,000 3720
1,000,001 - 2,150,400 9667
The above estimates are calculated based on the assumption that the
workload for update I/Os for the migrated volume is 50 IOPS for one volume.