Veritas File System 5.0 Administrator's Guide (September 2006)

limit the life of data Storage Checkpoints to minimize the impact on system
resources.
nodata Storage Checkpoints
A nodata Storage Checkpoint only contains file system metadata—no file data
blocks. As the original file system changes, the nodata Storage Checkpoint records
the location of every changed block. Nodata Storage Checkpoints use minimal
system resources and have little impact on the performance of the file system
because the data itself does not have to be copied.
In Figure 5-4, the first block originally containing A is updated.
The original data is not copied to the storage checkpoint, but the changed block
is marked in the Storage Checkpoint. The marker indicates which data has changed.
Figure 5-4
Updates to a nodata clone
A’
B
C
D
E
Storage CheckpointPrimary fileset
Removable Storage Checkpoints
A removable Storage Checkpoint can “self-destruct” under certain conditions
when the file system runs out of space.
75Storage Checkpoints
Types of Storage Checkpoints