Hard links are a feature of the Microsoft operating systems, and are used when CPS Exchange backup jobs are processed. When you review disk space availability for CPS Exchange backup jobs, hard links affect the amount of reported available disk space.
The scheduled CPS Exchange full backup creates a media with a name such as IMG000060. The recovery points create VDB subfolders under the IMG media with names such as vdb_2007_03_08_1735_08. The Exchange transaction log files are put into the IMG media during backup. The logs in the VDB subfolders are hard links to the Exchange transaction log files. As VDB subfolders are created, they contain all of the hard links from the previous recovery points until the next full backup runs.
VDB1 contains hard links to log files 1-5.
VDB2 contains hard links to log files 1-10.
VDB3 contains hard links to log files 1-15.
In this example, log files 1-5 are reported as having three times more space than they actually use.
A result of using hard links is that disk space usage appears to be greater than it is. For example, if 300 MB of disk space on a drive is used, it may appear that 500 MB of disk space is used. Be aware of this limitation when you review disk space availability for CPS Exchange backup jobs.
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