User Manual

Table Of Contents
Basic Snapshot Concepts
The ReadyNAS can provide protection of shares and LUNs through snapshots. Snapshots
contain references to data on a share or LUN. They take no space until the data they
reference is changed or deleted. Strictly speaking, snapshots are not backups, but they
function as backups because you can recover data from snapshots.
You can take snapshots only of shares or LUNs. You cannot take a snapshot of a volume.
Snapshots reside on the same volume as the share or LUN from which they were created.
The ReadyNAS can automatically take snapshots of a share or LUN according to a
schedule that you specify. You can also manually take or delete individual snapshots at
any time. Depending on available storage space, you can keep an unlimited number
of snapshots.
WARNING: When the available storage space on a volume decreases below a threshold
(set to a default of 5 percent) of the volume’s total storage space, the oldest automatic
snapshots are automatically deleted to bring the available storage space back to the
threshold or higher. Manual snapshots are never automatically deleted. The threshold
is part of the snapshot settings for a volume.
Once protection is available, the shares and LUNs on the Shares page indicate the
number of snapshots and the number of days with protection.
Figure 9. Share with daily snapshots
Note: For snapshots to be accessible to users from their network-attached device you
must select the Allow snapshot access check box in the share or LUN settings window.
For more information, see View and Change the Properties of a Shared Folder on page
64.
Note: Hourly snapshots are not taken for spun-down disks, but daily snapshots are
taken.
Software Manual125Snapshots
ReadyNAS OS 6.10