On Friday 24 October 2003 10:06, Hans Kinwel wrote:
>On Thu, Oct 23, 2003 at 11:05:57PM -0400, Gene Heskett wrote:
>> >> Generally speaking, dump is not the prefered utility for use
>> >> with amanda. We seem to have gradually come to prefer tar, in
>> >> any version 1.13-19 or higher.
>
>and
>
>> Most of the comments I've read on this list from folks who have
>> run dump, seem to be less than enthusiastic after it bites them in
>> a recovery attempt.
>
>and more.
>
>Personally, I am a content dump user and I never had any problem
>recovering. As far as I remember I have not seen any, or more than
> tar, failed recovery attempts on this mailinglist.
>
>Last week I decided to find out about the dump scare, as I seemed to
>remember that someone on this list said that dump is more or less as
>safe as tar is, given normal usage.
>
>Despite all my searching, I couldn't find that message on the list
> again. However, I found something better: the official word from
> the dump authors.
>
>Here it is. http://dump.sourceforge.net/isdumpdeprecated.html
>
>I encourage anyone interested to read it.
Thanks for that bit of reasearch, Hans.
And it does seem to be an unvarnished attempt to clarify the problems
and pitfalls of both approaches. If one can re-mount the filesystem
ro for the duration of the dump, this would seem to alleviate the
major headache. Or one can make a snapshot, but would not that
snapshot take up as much space as the original? And how long would
it take to do a snapshot on a 40gig filesystem?
In re tars mods to atime. I haven't gotten into a situation that
requires I survey that except when we were cleaning up a rootkit some
years ago. Objections to that might be fixed by having a different
open vector that was only available to tar and its ilk, and which
didn't modify the atime. Because of the time involved, and the
cacheing in the normal access, restoreing the atime doesn't seem to
me to be a wholly satisfactory solution, so the true bypassing would
seem to be the only solution for that.
As far as "file changed while we read it" messages from tar, I've seen
a bunch of them over the years but I have not yet been bit by
recovering a bad file that was important enough to make me mutter
about the authors geneology. I suppose that day will happen, Murphy
guarantees it will eventually.
I agree, everyone should read it, then make thier own mind up and live
with it.
At this point, and because I can break disklist entries up into
manageable pieces, I'll continue to use tar. To use dump, I'd have
to start by buying a tape drive about 10x bigger. Nah, not for a
home user, its not economically justifiable when I'm retired, meaning
I really should be watching how I spend my money.
--
Cheers, Gene
AMD K6-III@500mhz 320M
Athlon1600XP@1400mhz 512M
99.27% setiathome rank, not too shabby for a WV hillbilly
Yahoo.com attornies please note, additions to this message
by Gene Heskett are:
Copyright 2003 by Maurice Eugene Heskett, all rights reserved.
|
