VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Chapter 9, Using the Space Capacity Planning Utility for Storage Checkpoints
Prerelease 8 September 2005, 8:55am Planning File System Space for Storage Checkpoints
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Planning File System Space for Storage Checkpoints
VxFS file systems need extra disk space to store Storage Checkpoints. Because VxFS can remove
Storage Checkpoints when a file system runs out of space, it is important to ensure that you have
adequate space for Storage Checkpoints. The extra space needed depends on how the Storage
Checkpoints are used, the number of VxFS changed blocks recorded in the Storage Checkpoints,
the frequency with which you plan to create Storage Checkpoints, and how many Storage
Checkpoints you want to retain on your system at any given time.
You can use Storage Checkpoint Capacity Planning to simulate various Storage Checkpoint
creation and retention models in your production environment, collect the associated file system
space-usage information based on these models, and use this information to proactively determine
how much additional storage space is needed for Storage Checkpoints.
Storage Checkpoint Capacity Planning uses the cron command as the underlying mechanism to
run the Capacity Planning schedules you create. You must have the proper access and permissions
to create a cron job or the Capacity Planning schedule will fail to run.
All Storage Checkpoint Capacity Planning activities, including the file-level block change
information, is logged into the /etc/vx/vxdba/logs/ckptplan.log log file.