VERITAS File System 4.1 Administrator's Guide

Online Backup Using File System Snapshots
Snapshot File System Internals
Chapter 6126
should only require two to six percent of the blocks of the snapped file system. During periods
of high activity, the snapshot might require 15 percent of the blocks of the snapped file
system. These percentages tend to be lower for larger file systems and higher for smaller ones.
CAUTION If a snapshot file system runs out of space for changed data blocks, it is disabled
and all further access to it fails. This does not affect the snapped file system.