cleverhandle
Diamond Member
Just got a DDS-4 unit here, and I'm trying to learn my way around the *nix tape drive commands. Specifically, this is on OpenBSD, but I don't think it matters much in this case.
My main issue is that I don't quite get how rewinding works. I gather that, when you dump, the drive decides whether or not to rewind based on the device name - /dev/rst0 vs. /dev/nrst0 for me. Now, if my backups are not large and I want a couple weeks of incrementals on one tape, can I just choose not to rewind the tape at the end of a dump session, eject the tape, and pop it back in the next session? Also, if I do rewind, is there a way to append a new dump to the end of a tape? When I was experimenting yesterday, I sequentially dumped three small filesystems to nrst. I could then see the contents of each filesystem by doing restore -tvs X, where X was 1, 2, or 3. Before I went to bed, I wanted to add my large /home filesystem, so I did mt rewind and mt fsf 3, thinking this would put me at the end of the data on the tape. Ran the dump overnight, but checking it out this morning, I see that it occupied file space 1, overwriting the previous dumps. So is there some way to append that dump rather than overwriting?
And a minor issue: I notice that the beginning of the restore output gives something like
Level 0 dump of /dev/rraid0g (/home)
Label: None
Is there some way I can write the date to that label in order to conveniently review the archives on a tape? The dump man page didn't seem to mention anything.
My main issue is that I don't quite get how rewinding works. I gather that, when you dump, the drive decides whether or not to rewind based on the device name - /dev/rst0 vs. /dev/nrst0 for me. Now, if my backups are not large and I want a couple weeks of incrementals on one tape, can I just choose not to rewind the tape at the end of a dump session, eject the tape, and pop it back in the next session? Also, if I do rewind, is there a way to append a new dump to the end of a tape? When I was experimenting yesterday, I sequentially dumped three small filesystems to nrst. I could then see the contents of each filesystem by doing restore -tvs X, where X was 1, 2, or 3. Before I went to bed, I wanted to add my large /home filesystem, so I did mt rewind and mt fsf 3, thinking this would put me at the end of the data on the tape. Ran the dump overnight, but checking it out this morning, I see that it occupied file space 1, overwriting the previous dumps. So is there some way to append that dump rather than overwriting?
And a minor issue: I notice that the beginning of the restore output gives something like
Level 0 dump of /dev/rraid0g (/home)
Label: None
Is there some way I can write the date to that label in order to conveniently review the archives on a tape? The dump man page didn't seem to mention anything.
