Number of volumes, Auto migration planning, Auto migration execution – HP StorageWorks XP Remote Web Console Software User Manual

Page 17: Manual migration execution, Maintenance, Auto migration parameters, Powering off disk arrays

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Auto LUN XP user guide for the XP128/XP1024

17

Volumes Continuous Access XP Journal uses

Volumes specified with the Read Only or Protect attribute

Volumes that Volume Security disabled for use as secondary volumes

Volumes that LUN Security XP Extension specified as Read Only or Protect or disabled for use as

secondary volumes

Volumes reserved by a migration program other than Volume Migration

Number of volumes

In manual migrations, the number of migration plans that can be executed concurrently might be restricted,

depending on use of other Command View XP or XP Remote Web Console programs and emulation types

and sizes of migrated volumes. Therefore, the number of migration plans that can be executed concurrently

is not constant.
A maximum of 36 Auto LUN XP copy operations can be requested at the same time. Auto LUN XP performs

migration operations sequentially (one volume at a time).
The maximum number of Auto LUN XP copy operations plus BC pairs is 1024.

Auto migration planning

Auto LUN XP will not plan an auto migration when:

There is no reserve volume with the same emulation type and capacity as the source volume in the

same or next higher/lower HDD class (auto migration is performed only between consecutive classes or

within the same class)

Auto LUN XP cannot estimate the usage rate for the target parity group because of some condition (for

example, invalid monitor data)

The estimated usage of the target parity group or volume is over the user-specified maximum disk usage

value for that HDD class

The estimated performance improvement is not large enough

Auto migration execution

Auto LUN XP will not execute an auto migration operation when:

The current usage (last 15 minutes) of the source or target parity group or volume is over the maximum

disk usage rate for auto migration

The current write pending rate for the disk array is 60% or higher

Manual migration execution

Auto LUN XP will execute a manual migration operation when the current write pending rate for the disk

array is 60% or higher.

Maintenance

Do not perform Auto LUN XP migration operations during disk array maintenance activities (for example,

cache or drive installation, replacement, or de-installation).

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

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