Deleting backups

Methods of deleting backups

SnapManager provides the following ways to manage and delete backups:

You can manage the number of backups stored and delete older backups automatically using the Delete Oldest Backups In Excess Of feature in the SnapManager Backup window.
This is the recommended method. For details, see Deleting backups automatically.
You can use the Delete Backup option on the Action menu.
Note
This is the only way to delete snapshots created by SnapManager Restore.

For details, see Deleting backups using the Action menu.
You can delete selected backups individually.
For details, see Deleting selected backups.

Note
Do not use SnapDrive or the filer administration tools to delete snapshots created by SnapManager. Doing so will leave behind unwanted data that cannot be removed.

Option to retain up-to-the-minute restore ability

When you delete backups that are not the oldest backups in your backup list, and the corresponding transaction logs are also deleted, the older remaining backups are no longer available for an up-to-the-minute restore. This is because the logs are no longer contiguous from when the older backup was taken to the present time.

This can happen when you are deleting backups of a particular backup management group.

SnapManager for Microsoft Exchange enables you to preserve the logs in this case, thus retaining the ability to use the older backups in an up-to-the-minute restore.

Note
If you know you will not need to perform an up-to-the-minute restore from the older backups, you should allow the logs to be deleted, to free up more space on the filer holding the backups.

Example

Suppose that you have the following backups stored:

Now, you perform a Standard backup, and specify that only the four most recent Standard backups be retained. After this backup is complete, the oldest Standard backup is deleted, and the daily backup becomes point-in-time only:

To avoid this situation, you can use the option to retain up-to-the-minute restore ability for older backups, at the cost of using more space on your filer for the logs that are not deleted.

Problem deleting backups due to busy snapshot error

If you attempt to delete a backup and you get an error message saying that the snapshot is busy and cannot be deleted, you have a backup that was taken of a LUN backed by another snapshot. In this case, you need to delete the more recently taken backup before the older backup can be deleted.

To see if you have busy snapshots, you can view your snapshots in FilerView or use the filer snap list command. For more information about deleting busy snapshots, see the System Administration Block Access Guide for your version of Data ONTAP.

Note
To avoid this situation in the future, make sure that you do not take backups while you have any LUNs backed by snapshots (for example, during a verification or while archiving from a LUN backed by a snapshot). For more information about scheduling your SnapManager tasks, see Recommendations for scheduling backups and verifications.