Live mount operations use a 3DFS cache on the MediaAgent that performs the live mount. By default, the 3DFS cache is located in the Job Results folder for the MediaAgent; but you can change the path using the s3dfsRootDir additional setting. The 3DFS cache is circular; unused data are pruned from the cache as needed. By default 5% free space is maintained on the cache; but you can change the required percentage of free space using the n3dfsCacheMinFree additional setting.
The 3DFS cache is not used if you mount directly to an ESX host.
For each live mount job, the 3DFS cache requires minimum free space equal to the larger of the following values:
15% of the total VM size (the sum of the sizes of all VMDKs for the VM)
For faster recovery times, the 3DFS cache should be hosted on a solid state drive (SSD) using flash memory storage.