About extended-file marks for drives
If a tape drive supports extended file marks, you must configure it to use them (for example, 8-mm drives). Otherwise, NetBackup may not be able to use those drives.
For information, see the AIX chdev(1) and smit(1) man pages.
When you add a tape drive to NetBackup, NetBackup issues the chdev command to configure the drive to use extended file marks. For reference, the following is the command that NetBackup uses:
/usr/sbin/chdev -l Dev -a extfm=yes
Replace Dev with the logical identifier for the drive (such as rmt0 or rmt1)
Therefore, you do not have to configure the drive manually for extended file marks.