Copying file systems

[Jim Jagielski]

Many moons ago (well, a few then) there was a discussion here on c.u.a
concerning the "best" way to copy entire file systems: tar, cpio, dump.bsd or
whatever. I wrote that, IMHO, using tar didn't make sense, since it has trouble
with special file types; using find and cpio required filtering out the mount
point of the new file system to prevent copying copys. Now this isn't all that
difficult, but it does add a level of complexity and it DOES change file time-
stamps, which may not be such a good thing. I suggested that using dump.bsd and
restore in a simple pipe was the way to go:

   $ dump.bsd -t 4.2 0uf - /dev/rdsk/cxdysz | (cd /mnt; restore -T 4.2 xf - )

Of course, you could dump to tape and then restore from it, but this takes much
longer.

Well, I just moved my A/UX system to 2 335 MB Wren Runners using the above
method and I have a few observations to share:

	1. This method, more specifically restore (I think) had trouble
	   "copying" named pipes. In my configuration there were only
	   2 (lib/cron/FIFO and lpd/AppleTalk/pipe) and after the dump/restore
	   I simply copied them over... restore said something about an
	   "unknown mode 010xxx" where xxx was either 660 or 666.

	2. All symbolic links were (re-)created with an owner and group of
	   root. Of course, this really doesn't matter, since the owner, group
	   and mode of a link doesn't mean all that much, but it still is
	   a change over what the file-system looked like before...

Everything else went off without a hitch...

Oh yeah, by the way. The correct /etc/disktab entry for the 335MB Wren Runner
(ST 4385D, 385H: 94181-385) is:

	# Wren 4385
	#
	WR385|Runner|ST4385:\
		:ty=winchester:ns#56:nt#15:nc#791:

At least, that's what the Seagate spec-sheet says :)
--
===========================================================================
#include <std/disclaimer.h>
                                 =:^)
           Jim Jagielski                    NASA/GSFC, Code 711.4
     jim at jagubox.gsfc.nasa.gov               Greenbelt, MD 20771

"If we increase the size of the penguin until it is the same height as a man
 and then compare the relative brain size, we know find that the penguin's
 brain is still smaller. But, and this is the point, it is larger than it WAS!"