Calculating VTL/VTD Space Requirements (4045541)

There is a slight disk space overhead when creating a Virtual Tape Library or Virtual Tape Drive. It is dependent upon the filesystem being used, and how the library is configured in relationship to the capacity and number of slots being created.

The table below is the result of internal testing and is provided as an example. Your individual results may vary.

Number of Slots * Capacity Linux (ext3) Windows (FAT32) Windows (NTFS)
4 slots * 50 MB 0.2 MB 0.09 MB 0.005 MB
40 slots * 50 MB 2.5 MB 0.65 MB 0.04 MB
60 slots * 50 MB 3.7 MB 0.96 MB 0.06 MB
30 slots * 50 MB 1.9 MB*** 0.50 MB 0.03 MB
30 slots * 100 MB 3.3 MB*** 0.50 MB 0.03 MB

*** We expected value to be same (since the number of slots is same), but on Linux it seemed to be different. This could very well be due to the block size in use by the filesystem.