Multiple backups to one tape

[Rajesh Rambally]

Hello,
I currently backup a directory to tape every month. Is it possible to backup more than one month to a single tape where after each month I have to eject the tape. When I use the tape again, how can I avoid what is currently on the tape from being overwritten? I know I can use the norewind option and create more than one fileset with multiple vdump commands but this is when the tape remains in the drive.

Thanks
Rajesh

[Ivan Ferreira]

Use the no rewind tape device, for example:

vdump -0uf /dev/ntape/tape0c /
vdump -0uf /dev/ntape/tape0c /usr
vdump -0uf /dev/ntape/tape0c /var

To list the first backup:

mt -f /dev/ntape/tape0c rewind
vdump -tf /dev/ntape/tape0c

To list the third backup, skip two filesets:

mt -f /dev/ntape/tape0c fsf 2
vdump -tf /dev/ntape/tape0c

[Steven Schweda]

"man mt"

mt -f non-rewind_tape_device fsf [count]

If you don't know the proper count, I
believe that you can simply repeat this
command with count = 1 until you get an
error.

[Victor Semaska_3]

Yes, repeating the command until you get a non-zero return code works. I have a script that uses that technique. We start new system logs on the 1st of the month and the script appends the previous month's logs to tape for archiving.

Vic

[Mark Poeschl_2]

Many types of tape drives also respond to the 'seod' directive which always takes you to the end of any valid data on the tape:

# mt -f /dev/ntape/tape0_d1 seod