how to use tar

how to use tar to backup to tape?

what is different between rmt0 rmt1 ... rmt 12?

what is different between rewind or not?

please give me an example for it

tar cvf /dev/rmt0 file1 file2 file3

or

tar cvf /dev/rmt0 *

to write stuff on to a tape

tar xvf /dev/rmt0 to get it off.

/dev/rmt0 varies from platform to platform, the different formats can indicate multiple tape drives, different densities etc

hth
connor