IBM System Storage DS3000, Programming Manual

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v retainCount
– This parameter keeps the most recent Enhanced FlashCopy images in the consistency
group, and delete the older FlashCopy images.
v enhancedFlashCopyImageId
- The only value that be used with this parameter is
OLDEST
to delete only
the oldest Enhanced FlashCopy image.
If you have an Enhanced FlashCopy logical drive associated with the to-be-deleted Enhanced FlashCopy
images, you can choose to either stop the deletion operation or continue with the deletion anyway. To
continue with the deletion whether the Enhanced FlashCopy images have associated Enhanced
FlashCopy logical drives or not, set the
ignoreEnhancedFlashCopylogicalDrive
parameter to
TRUE
. To stop
the deletion when the Enhanced FlashCopy image has the associated Enhanced FlashCopy logical drive,
set the
ignoreEnhancedFlashCopylogicalDrive
parameter to
FALSE
. The default is
FALSE
. This parameter
applies only if the Enhanced FlashCopy image is associated with an Enhanced FlashCopy logical drive.
Creating a Consistency Group Enhanced FlashCopy logical drives
A consistency group Enhanced FlashCopy logical drive contains several Enhanced FlashCopy logical
drives to provide host access to an Enhanced FlashCopy image that has been taken for each selected
member logical drive at the same moment in time.
The consistency group Enhanced FlashCopy logical drive can be designated as either read-only or
read-write. Read-write consistency group Enhanced FlashCopy logical drives require a repository for each
member logical drive that you select to save any subsequent modifications made by the host application
to the base logical drive without affecting the referenced Enhanced FlashCopy image. Each member
repository is created at the same time the consistency group Enhanced FlashCopy logical drive is created.
Note:
A read-write Enhanced FlashCopy logical drive requires an overall repository. The overall
repository is created initially with one individual repository logical drive. However, the overall repository
can contain multiple repository logical drives in the future for expansion purposes.
Prerequisites
v
The Enhanced FlashCopy premium feature must be enabled on the storage subsystem.
v
The consistency group must contain at least one member logical drive before you can create a
consistency group Enhanced FlashCopy logical drive.
Guidelines
Keep these guidelines in mind when creating a consistency group Enhanced FlashCopy logical drive:
v
There is a maximum of 512 Enhanced FlashCopy images for the DS3500 and DCS3700 controller
subsystems.
v
There is a maximum of 2048 Enhanced FlashCopy images for the DCS3700 storage subsystem with
Performance Module Controllers controller subsystem.
v
You cannot create an Enhanced FlashCopy logical drive of a failed logical drive.
v
Enhanced FlashCopy logical drive repositories are fully resize-able. If you have the storage capacity
you can increase the size of the Enhanced FlashCopy repository to avoid a repository full message.
Conversely, if you find that the Enhanced FlashCopy logical drive repository is larger than you need,
you can reduce its size to free up space that is needed by other logical drives.
v
If you attempt to create an Enhanced FlashCopy logical drive for an Enhanced FlashCopy image and
that Enhanced FlashCopy image is in a pending Enhanced FlashCopy image creation operation it is
due to the following conditions:
– The base logical drive that contains this Enhanced FlashCopy image is a member of an Enhanced
Global Mirror Group AND
– The base logical drive is currently in a synchronizing operation. The Enhanced FlashCopy image
creation will complete as soon as the synchronization operation is complete.
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IBM System Storage DS3000, DS4000, and DS5000: Command Line Interface and Script Commands Programming Guide