H06.24 Release Version Update Compendium

7 Hardware Products
Tape Backup/Restore FSF Emulation
The EmulateFSF emulator is a new feature for restore operations. EMULATEFSF emulates a File
Space Forward SCSI operation. This option is meant to allow faster partial restores or LISTONLY
restores on specific tape drives where the tape firmware is apparently slower in doing the same
operation.
Guidelines for using EMULATEFSF are:
• The usage of EMULATEFSF is meant only for M8501 and M8502 models of LTO-3 Tape drives
and should not be used with any other drives. Virtual and other physical tape drives may not
show any performance improvement for restore operations and may in fact be slower with
this option.
• It is advised to use the EMULATEFSF option in a non-CLIM setup only, as a CLIM-based setup
would slow down the performance.
• The file-mode options that are meaningful with the EMULATEFSF option is LISTONLY.
• Using EMULATEFSF speeds up LISTONLY and PARTIAL in some specific types of physical Tape
drives such as the M8501 and M8502 models of LTO-3 tape drives.
• You cannot use the EMULATEFSF option with the VOLUMEMODE restore option.
• The option is known to work best with small files, less than 3 MB file size, in a reasonably
small sized backup image.
With very large average file sizes of about 30 MB and a huge total backup size greater than 19
GB, EMULATEFSF would have negative performance impact.
Migration Considerations
None.
Fallback Considerations
None.
16 Hardware Products