Good afternoon mmagbee,

The SharePoint Server agent caches the information that it downloads to the job results directory. You may not observe this behavior on other SharePoint systems because they could potentially service a different farm and have smaller sites. We will by default cache two sites at a time during the backup process. If you are running both the SharePoint Server document, and SharePoint Server database at the same time it will also increase the space used. If you are unable to allocate space and running both SharePoint Document and SharePoint Database at the same time it may be beneficial to stagger the jobs so that they are not running at the same time.

Below I have listed some information on how to prepare for this by allocating the correct amount of space to the job results directory.

http://documentation.commvault.com/commvault/v11_sp16/article?p=2994_1.htm

Under the Hard Drive section review the following.
* For Databases, Job Results folder size should be twice the size of the largest service applications database size.
* For Documents, Job Results folder size should be twice the size of the largest subsite.

This Job results directory can be relocated to a different volume by following the steps below.http://documentation.commvault.com/commvault/v11_sp16/article?p=6588.htm

Thanks
~Brian