Dell NetWorker 19.9 Administration Guide

Windows Data Deduplication Volume Best Practices

Review the following information, which describes the recommended best practices when you backup volumes that have Windows data deduplication enabled.

• A full backup should be performed immediately after deduplication has been enabled on a volume.
• Windows performs garbage collection on the chunk store of each deduplicated volume to remove no-longer-used chunks. By default, a garbage collection job is scheduled weekly for data deduplicated volumes. A full backup should be scheduled to run after garbage collection, because the garbage collection job may result in many changes in the chunk store, as a result of file deletions since the last garbage collection job.
• If there is significant chunk store container activity, control the size of incremental backups by limiting the frequency of Windows deduplication optimization jobs.
• Avoid performing extremely large file level restores. If a large percentage of a volume is restored, it is more time efficient to restore the entire volume. Because file level restores recover files in rehydrated form, a file level restore that includes many files might take up more space than is available on the volume.
• If a large file level restore is to be performed, first perform a full backup of the volume in its current state.
• When you choose to unoptimize many files at once from an optimized deduplication backup, the process can take a significant period of time. The selected files restore feature is best used to restore a moderate number of files. If most of a volume is to be restored, a full volume restore is a preferred solution. If a small amount of data needs to be skipped, that data can be moved to a temporary storage area, then back to its original location after the volume level restore is completed.