15 Useful Linux and Unix Tape Managements Commands For Sysadmins

1: Display status of the tape/drive

mt status #Use default mt -f /dev/rmt/0 status #Unix mt -f /dev/st0 status #Linux mt -f /dev/nsa0 status #FreeBSD mt -f /dev/rmt/1 status #Unix unity 1 i.e. tape device no. 1

You can use shell loop as follows to poll a system and locate all of its tape drives:

for d in 0 1 2 3 4 5 do mt -f "/dev/rmt/${d}" status done

2: Rewinds the tape

mt rew mt rewind mt -f /dev/mt/0 rewind mt -f /dev/st0 rewind

3: Eject the tape

mt off mt offline mt eject mt -f /dev/mt/0 off mt -f /dev/st0 eject

4: Erase the tape (rewind the tape and, if applicable, unload the tape)

mt erase mt -f /dev/st0 erase #Linux mt -f /dev/rmt/0 erase #Unix

5: Retensioning a magnetic tape cartridge

If errors occur when a tape is being read, you can retension the tape, clean the tape drive, and then try again as follows:

mt retension mt -f /dev/rmt/1 retension #Unix mt -f /dev/st0 retension #Linux

6: Writes n EOF marks in the current position of tape

mt eof mt weof mt -f /dev/st0 eof

7: Forward space count files i.e. jumps n EOF marks

The tape is positioned on the first block of the next file i.e. tape will position on first block of the field

mt fsf mt -f /dev/rmt/0 fsf mt -f /dev/rmt/1 fsf 1 #go 1 forward file/tape

8: Backward space count files i.e. rewinds n EOF marks

The tape is positioned on the first block of the next file i.e. tape positions after EOF mark 

mt bsf mt -f /dev/rmt/1 bsf mt -f /dev/rmt/1 bsf 1 #go 1 backward file/tape

Here is a list of the tape position commands:

fsf Forward space count files. The tape is positioned on the first block of the next file.   fsfm Forward space count files. The tape is positioned on the last block of the previous file.   bsf Backward space count files. The tape is positioned on the last block of the previous file.   bsfm Backward space count files. The tape is positioned on the first block of the next file.   asf The tape is positioned at the beginning of the count file. Positioning is done by first rewinding the tape and then spacing forward over count filemarks.   fsr Forward space count records.   bsr Backward space count records.   fss (SCSI tapes) Forward space count setmarks.   bss (SCSI tapes) Backward space count setmarks.

Basic backup commands

Let us see commands to backup and restore files

9: To backup directory (tar format)

tar cvf /dev/rmt/0n /etc tar cvf /dev/st0 /etc

10: To restore directory (tar format)

tar xvf /dev/rmt/0n -C /path/to/restore tar xvf /dev/st0 -C /tmp

11: List or check tape contents (tar format)

mt -f /dev/st0 rewind; dd if=/dev/st0 of=-   ## tar format ## tar tvf {DEVICE} {Directory-FileName} tar tvf /dev/st0 tar tvf /dev/st0 desktop tar tvf /dev/rmt/0 foo > list.txt

12: Backup partition with dump or ufsdump

## Unix backup c0t0d0s2 partition ## ufsdump 0uf /dev/rmt/0 /dev/rdsk/c0t0d0s2   ## Linux backup /home partition ## dump 0uf /dev/nst0 /dev/sda5 dump 0uf /dev/nst0 /home   ## FreeBSD backup /usr partition ## dump -0aL -b64 -f /dev/nsa0 /usr

12: Restore partition with ufsrestore or restore

## Unix ## ufsrestore xf /dev/rmt/0 ## Unix interactive restore ## ufsrestore if /dev/rmt/0   ## Linux ## restore rf /dev/nst0 ## Restore interactive from the 6th backup on the tape media ## restore isf 6 /dev/nst0   ## FreeBSD restore ufsdump format ## restore -i -f /dev/nsa0

13: Start writing at the beginning of the tape 

## This will overwrite all data on tape ## mt -f /dev/st1 rewind   ### Backup home ## tar cvf /dev/st1 /home   ## Offline and unload tape ## mt -f /dev/st0 offline

To restore from the beginning of the tape:

mt -f /dev/st0 rewind tar xvf /dev/st0 mt -f /dev/st0 offline

14: Start writing after the last tar

## This will kee all data written so far ## mt -f /dev/st1 eom   ### Backup home ## tar cvf /dev/st1 /home   ## Unload ## mt -f /dev/st0 offline

15: Start writing after tar number 2

## To wrtite after tar number 2 (should be 2+1) mt -f /dev/st0 asf 3 tar cvf /dev/st0 /usr   ## asf equivalent command done using fsf ## mt -f /dev/sf0 rewind mt -f /dev/st0 fsf 2

To restore tar from tar number 2:

mt -f /dev/st0 asf 3 tar xvf /dev/st0 mt -f /dev/st0 offline

Please do add if i have missed some commands.