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Multiple backups to one tape

Rajesh Rambally
Occasional Visitor

Multiple backups to one tape

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
4 REPLIES
Ivan Ferreira
Honored Contributor

Re: Multiple backups to one tape

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
Por que hacerlo dificil si es posible hacerlo facil? - Why do it the hard way, when you can do it the easy way?
Steven Schweda
Honored Contributor

Re: Multiple backups to one tape

"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
Esteemed Contributor

Re: Multiple backups to one tape

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
There are 10 kinds of people, one that understands binary and one that doesn't.
Mark Poeschl_2
Honored Contributor

Re: Multiple backups to one tape

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