Data replication and backup with deduplication

When deduplicated files are replicated to another Isilon cluster or backed up to a tape device, the deduplicated files no longer share blocks on the target Isilon cluster or backup device. However, although you can deduplicate data on a target Isilon cluster, you cannot deduplicate data on an NDMP backup device.

Shadows stores are not transferred to target clusters or backup devices. Because of this, deduplicated files do not consume less space than non-deduplicated files when they are replicated or backed up. To avoid running out of space, you must ensure that target clusters and tape devices have enough free space to store deduplicated data as if the data had not been deduplicated. To reduce the amount of storage space consumed on a target Isilon cluster, you can configure deduplication for the target directories of your replication policies. Although this will deduplicate data on the target directory, it will not allow SyncIQ to transfer shadow stores. Deduplication is still performed by deduplication jobs running on the target cluster.

The amount of cluster resources required to backup and replicate deduplicated data is the same as for non-deduplicated data. You can deduplicate data while the data is being replicated or backed up.