Flashcopy Logical Drives; Volumecopy; Dynamic Logical Drive Expansion (Dve) - IBM System Storage DS3000 Programming Manual

The Volume-to-LUN mapping lets you define which host group or host has access to a particular logical
drive in the storage subsystem.
When you create storage partitions, define the partitions after you have created the primary logical drive
and the secondary logical drive in a Enhanced Remote Mirroring configuration. The storage partition
definitions for the primary storage subsystem and the secondary storage subsystem are independent of
each other. If these definitions are put in place while the logical drive is in a secondary role, the
administrative effort associated with the site recovery is reduced if it becomes necessary to promote the
logical drive to a primary role.

FlashCopy Logical Drives

A FlashCopy logical drive is a point-in-time image of a logical drive. Typically, it is created so that an
application, such as a backup application, can access the FlashCopy logical drive and read the data while
the base logical drive stays online and is accessible to hosts.
The logical drive for which the point-in-time image is created is known as the base logical drive and
must be a standard logical drive in the storage subsystem. The FlashCopy repository logical drive stores
information about all data that changed since the FlashCopy was created.
In this version of the storage management software, you can create FlashCopy logical drives based on the
primary logical drive or secondary logical drive of a remote mirror.

VolumeCopy

The VolumeCopy premium feature copies data from one logical drive (the source logical drive) to another
logical drive (the target logical drive) within a single storage subsystem. You can use this feature to
perform these functions:
v Copy data from subsystems that use smaller-capacity disk drives to subsystems that use larger-capacity
disk drives
v Back up data
v Restore FlashCopy logical drive data to the base logical drive.
You can use a primary logical drive in a remote mirror as a source logical drive or a target logical drive
in a VolumeCopy. You cannot use a secondary logical drive as a source logical drive or a target logical
drive.
Note: If you start a role reversal during a copy-in-progress, the copy fails and cannot be restarted.

Dynamic Logical Drive Expansion (DVE)

A Dynamic Volume Expansion (DVE) is a modification operation that increases the capacity of a standard
logical drive or a FlashCopy repository logical drive. The increase in capacity is achieved by using the
free capacity that is available in the subsystem of the standard logical drive or the FlashCopy repository
logical drive.
This modification operation is considered to be "dynamic" because you can continually access data on
subsystems, logical drives, and disk drives throughout the entire operation.
A DVE operation can be performed on a primary logical drive or a secondary logical drive of a mirror
relationship.
Note: Although the storage management software indicates that the logical drive has increased capacity,
its usable capacity is the size of the smaller of the primary logical drive or the secondary logical drive.
You cannot perform a DVE operation on a mirror repository logical drive.
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IBM System Storage DS3000, DS4000, and DS5000: Command Line Interface and Script Commands Programming Guide