When you create a FlashCopy logical drive, you specify where to create the repository logical drive, its capacity, threshold level warning, and other parameters. The repository logical drive capacity is created as a percentage of the base logical driveand contains the copy-on-writedata. The storage management software provides a warning message when your repository logical drive exceeds the threshold level.
Important:
The repository logical drive's failure policy determines what happens when the repository logical drive becomes full (that is, all of its capacity has been used). The failure policy can be set to either fail the FlashCopy (default setting) or fail incoming I/O to the FlashCopy's base logical drive.
Do not ignore the repository logical drive "threshold exceeded" notification. This is the last and only warning you will receive before the FlashCopy's repository logical drive becomes full. You have the option of increasing the capacity of the repository logical drive or increasing the repository logical drive threshold capacity warning level. Increasing the warning threshold will reduce the time you have to respond the next time you receive a threshold exceeded notification.
If a FlashCopy logical drive or repository logical drive is displayed as a missing logical drive, the storage subsystem has detected drives associated with the FlashCopy or repository logical drive are no longer accessible. Missing logical drives, in most cases, are recoverable. For more information, see Learn About Missing Logical Drives.
FlashCopy Logical Drive Maintenance
The default repository logical drive capacity is set to 20% of the base logical drive, that is if enough free capacity exists to create a repository logical drive of this size. The default threshold level for the repository logical drive is set to 50%. If you are not sure how large to make the repository logical drive or how high to set the repository logical drive full warning, accept the default settings. You can estimate later how quickly the FlashCopy's repository capacity is being used. For more information, see Learn About Estimating Repository Logical Drive Life Expectancy.
Viewing FlashCopy Logical Drive Failure Settings
To see the current failure settings:
1
Select a repository logical drive in the Logical View of the Subsystem Management Window.
2
Select either the Logical Drive >> Properties pull-down menu option, or Properties from the right-mouse pop-up menu.
Result: The Repository Logical Drive - Properties dialog is displayed.
3
Select the Capacity tab to view the currently defined settings.
If the repository logical drive is set to fail the FlashCopy logical drive when it becomes full, its data will not be recoverable and the FlashCopy cannot be accessed. The only available option (if this situation occurs) is to delete the FlashCopy logical drive or re-create the FlashCopy logical drive to create a new point-in-time image.
If the repository logical drive is set to fail writes to the base logical drive, the data is recoverable, but the repository logical drive capacity must be increased before writes to the base logical drive are not rejected. For more information, see Increasing the Capacity of a Repository Logical Drive.
Important:
Deleting a FlashCopy logical drive automatically deletes the associated repository logical drive.
Deleting a repository logical drive automatically deletes the associated FlashCopy logical drive.
Deleting a FlashCopy logical drive and then creating it again forces you to stop the host application and unmount the base logical drive while the FlashCopy is being created again.
Re-creating a FlashCopy logical drive alleviates the need to create a repository logical drive, as well as re-map the assigned logical drive-to-LUNmappings between the FlashCopy logical drive and the host.
After the FlashCopy logical drive is re-created, you can change parameters on the repository logical drive through the appropriate menu options.