TAR and CPIO (Was:Re: SCSI tape drive)

[Alexis Rosen]

jim at jagubox.gsfc.nasa.gov (Jim Jagielski) writes:
>alexis at panix.uucp (Alexis Rosen) writes:
>>The problem is, "working" doesn't mean "releasable". Tar and cpio will fail
>>with any large job (trivial ones work). Dump and restore work, but I've seen
>>problems there too- restore not wanting to restore and suchlike.
>My system is relatively medium in size :
>/             53398 blocks used of  102508 total. (52.09%):   /dev/dsk/c0d0s0
>/usr2         59426 blocks used of  154418 total. (38.48%):   /dev/dsk/c5d0s3
>/usr          71524 blocks used of  190782 total. (37.49%):   /dev/dsk/c0d0s2
>
>and I backup each partition using cpio and the st driver. I've not hit a
>snag yet when backing-up and have not required extensive restoring yet, all-
>though I have done a cpio -pdmuv from /usr2 to /usr/usr2 when I reformatted
>/usr2 to BSD Fast File (after I updated to 2.0) and then back again to /usr2
>without problems (/ and /usr are on a Wren 170, /usr2 is Quantum 80).
>
>Have I been lucky or haven't I reached the size limit yet?

First of all, this problem only seems to happen with tapes. cpio -p has always
worked for me, with consideerably larger things than your /usr2.
As for backing up something that size, I haven't tried it. The author says,
st _does_ fail. I'm not interested in finding out that I'm the exception
_after_ I need to restore. However, to be honest, it's supposed to crash
during backup. I don't know why yours hasn't. Perhaps a chat with MicroNet
will clear things up. I'll call them monday...

>By the way, isn't A/UX distributed in cpio format? Therefore, cpio must be
>able to restore A/UX entirely from the distribution medium... true, it's
>less than 50Megs, but I wouldn't call it "trivial".

As I think has been made clear, it works with the Apple tape, for less than
one tape _only_ (as you're well aware, I recall...). Nothing else, that I
know of, has been shown to work.

>Anyone know if any of the 3rd party tar/cpio replacements ("CTar", "LoneTar"(?)
>) have been ported to A/UX?
>
>Finally, what about pax?

Well, I just tried it to read a tar archive I had made (a small one). No dice.
Might not have been pax's fault, though, so I can't say anything. Except
that I wish the folks at Apple would fix Major Screwup #2 so that we can
get on with our lives (serial stuff being #1...). A/UX is a wonderful product.
When my disk crashes, I'll be able to say "A/UX _was_ a wonderful product."
And that's all.

---
Alexis Rosen
Owner/Sysadmin, PANIX Public Access Unix, NY
{cmcl2,apple}!panix!alexis