appending dump backups
 

I have a query regarding how to use dump to backup a series of file systems to a single tape. I discovered that after the first dump the tape rewinds so any dump backups run afterwards will start at the beginning of the tape again and overwrite the data that has just been backed up.

I found that if you use the nst tape device instead of st the tape should not automatically rewind, but after changing my script to use /dev/nst0 it looks like the tape is still going back to the beginning. When each dump starts the message below is logged:
"Volume 1 started with block 1 at: <date>"

I would expect the later jobs not to be starting at block 1 if the backups are being appended.

The script uses the commands below.

/sbin/dump -0u -f /dev/nst0 /
/sbin/dump -0u -f /dev/nst0 /fs1
/sbin/dump -0u -f /dev/nst0 /fs2

What do I have to do to get fs1 and fs2 to backup on the end of the tape?

After some testing I found it does actually start writing the tape at the end of the previous dump when you use the nst0 device, although it says "started with block 1". Once all the backups complete you need to do
mt -f /dev/nst0 rewind