Veritas File System 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

limit the life of data Storage Checkpoints to minimize the impact on system
resources.
See “Showing the difference between a data and a nodata Storage Checkpoint”
on page 87.
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 6-4, 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 6-4
Updates to a nodata clone
A’
B
C
D
E
Storage CheckpointPrimary fileset
See “Showing the difference between a data and a nodata Storage Checkpoint”
on page 87.
81Storage Checkpoints
Types of Storage Checkpoints