NetWorker 19.7 Snapshot Management Integration Guide

Example of a destructive rollback

Three file systems, /fs1, /fs2, and /fs3, exist on a LUN, which resides on a storage array standard device. You create a snapshot for the /fs1 file system. Because /fs2 and /fs3 also reside on the LUN, the snapshot includes those file systems. After the snapshot, you create a fourth file system, /fs4, on the LUN.

If you perform a rollback of /fs1, the snapshot will overwrite the contents of the entire LUN. The rollback will revert the contents of /fs1, /fs2, and /fs3, and it will destroy the new /fs4 file system. Although NSM safety checks do not normally allow a rollback overwrite such as this, exceptions can occur. The exceptions occur when you roll back with the force option or when /fs2, /fs3, and /fs4 are present in the psrollback.res file. Either exception will destroy /fs4 and roll back /fs2 and /fs3.