Click the Admin tab.
Click the Settings tab.
Scroll to the Disk Limit Settings section.
The disk limit settings define watermarks for the free space and server cache space.
The Safety Free Limit is the free space high water mark, and should be set to 5-10% of the disk. Half of this is the low water mark.
The Minimum Cache Size is the desired cache space, and should be set so that it reserves to 2-3 times the daily study volume.