QFS supports some volume management capabilities, allowing many disks to be grouped together into a file system.
SAM extends the QFS file system transparently to archival storage.
A SAM-QFS file system may have a relatively small (gigabytes to terabytes) "disk cache" backed by petabytes of tape or other bulk storage.
Files are copied to archival storage in the background, and transparently retrieved to disk when accessed.
[3] The lead architect of SAM-QFS was Harriet Coverston, the founder and VP of Technology at LSC.