ReadyNAS Pro Business Edition User Guide
Disk space utilization field on the Volume screen shows how much space has been reserved for snapshots.
Figure
After the snapshot is taken, if changes on the volume exceed this reserved space, the snapshot is invalidated and can no longer be used.
Note: Changes that occupy space in the reserved snapshot space include new file 
creation, modifications, and deletions; for instance, any time you delete a 1MB file,
the change caused by the deletion uses up 1MB of reserved space.
When the snapshot does become invalidated, an
Resizing Snapshot Space
If you are constantly getting snapshot invalidation alerts, you might want to either increase the frequency of the snapshot or consider increasing the reserved snapshot space. To do this, or to eliminate your existing snapshot space (thus increasing your usable volume space), you can specify the snapshot space you want in the Snapshot Space section. Simply select a value from the
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Securing Your Data |