[rescue] Mounting and Dumping

Mike Meredith mike at blackhairy.demon.co.uk
Wed Jan 14 16:53:12 CST 2004

On Wed, 14 Jan 2004 16:42:42 -0500, Sheldon T. Hall wrote:
> Of course, what's _really_ bad is that ufsdump doesn't tell you it's
> writing crap; you only find that out when you try to restore from your
> backup.

True enough. Mind you some of the others can be just as bad ... see
http://berdmann.dyndns.org/zwicky/testdump.doc.html. One of my
coworkers says that the one thing he doesn't like about Unix is that
there's multiple ways of doing backups and all of them seem to have
problems (and likes to point out that VMS has just one that works).

> >  (Read all the way through all the responses to that one)
> No consistent message there ... some say it's OK, some say it's not.

That's the problem. I suspect it's pretty rare that there's a problem,
but then again I suspect that there's plenty of people having problems
with ufsdump that don't notice ... because they don't test their
backups. Stopping syslogd could be something that's overlooked in some
of the problem cases.

> I find it interesting that SGI does things quite differently.  xfsdump
> will_only_ dump mounted filesystems, according to the man page, and
> the SGI GUI backup thingie uses cpio rather than xfsdump anyway.

They aren't the only ones ... the AdvFS dump for Digital Unix also
requires a mounted filesystem. Interestingly the IRIX dump for efs
requires you to unmount the filesystem ... I guess SGI had enough
complaints about this for fixing dump to be an item on the list of
things to do for XFS.

> > Yes I know I'm not in agreement with the majority view here which
> > means I'm probably wrong :)
> Oh, I wouldn't say that.

But perhaps a little paranoid about backups. Having once had a 20-hour
day trying to restore a system (and encountering bad tapes) with the
Director of Finance having a nervous breakdown behind me has left a
lasting impression :)

> > Not streaming is (long term) a recipe for dead tapes
> > and drives.
> Yep.  Been there.  Done that.  Remember those sucky little Colorado
> drives that ran off the floppy disk cable on a PC?

Still got one around here somewhere, and a collection of the tapes
sitting in my desk at work. Even better I've got a 9-track tape on my
desk to scare PFY's with.

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