Storage Checkpoint Quotas

VxFS provides options to the fsckptadm command interface to administer Storage Checkpoint quotas. Storage Checkpoint quotas set limits on the number of blocks used by a primary fileset and all of its related Storage Checkpoints.

hard limit	An absolute limit that cannot be exceeded. If a hard limit is exceeded, all further allocations on any of the Storage Checkpoints fail, but existing Storage Checkpoints are preserved.
soft limit	Must be lower than the hard limit. If a soft limit is exceeded, no new Storage Checkpoints can be created. The number of blocks used must return below the soft limit before more Storage Checkpoints can be created. An alert and console message are generated.

In case of a hard limit violation, two solutions are possible, enacted by specifying or not specifying the -f option for the fsckptadm utility (see the fsckptadm(1M) manual page):

• If the -f option not is specified, one or many removable Storage Checkpoints are deleted to make space for the operation to succeed. This is the default solution.
• If the -f option is specified, all further allocations on any of the Storage Checkpoints fail, but existing Storage Checkpoints are preserved.

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  Note    Sometimes if a file is removed while it is opened by another process, the removal process is deferred until the last close. Because the removal of a file may trigger pushing data to a "downstream" Storage Checkpoint (that is, the next older Storage Checkpoint), a fileset hard limit quota violation may occur. In this scenario, the hard limit is relaxed to prevent an inode from being marked bad. This is also true for some asynchronous inode operations.

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