Date: Mon, 03 Jul 2006 16:46:39 +0100 From: Alex Zbyslaw <xfb52@dial.pipex.com> To: backyard1454-bsd@yahoo.com Cc: freebsd-questions@freebsd.org Subject: Re: problems with Nice and Dump in FreeBSD 6.1-Current (Stable-#5) Message-ID: <44A93BDF.4050601@dial.pipex.com> In-Reply-To: <20060630191357.43491.qmail@web81615.mail.mud.yahoo.com> References: <20060630191357.43491.qmail@web81615.mail.mud.yahoo.com>
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backyard1454-bsd@yahoo.com wrote: >--- Alex Zbyslaw <xfb52@dial.pipex.com> wrote: > > > >>backyard1454-bsd@yahoo.com wrote: >> >> >> >>>I forgot about nice being interal to csh, that is >>>likely to source of my problems... >>> >>>I use this for a dump >>> >>>dump -0 -C 32 -f - |bzip2 --best | dd >>> >>> >>of=/foo/bar.dbz2 >> >> >>>and then on a restore >>> >>>bzip2 -dc | (cd /foo; restore -r -f -) >>> >>> >>>the error I get is >>> >>>expected 234234 got 234237 >>>expected 234235 got 234238 >>>expected 234236 got 234239 >>>... ... >>> >>>expected 234250 got 234267 >>> >>>which fills up the screen with seemingly corruption >>>errors, then the restore bails with an error asking >>> >>> >>if >> >> >>>I wish to continue, if I continue it fails. I will >>> >>> >>get >> >> >>>a screen dump of the error when I can dig up the >>>corrupt dump file, and or make a new one. I believe >>>the error is something about inodes missing or >>> >>> >>being >> >> >>>corrupted. >>> >>>this exact command syntax works on everything but >>> >>> >>my >> >> >>>usr filesystem. >>> >>> >>> >>> >>The restore man page does tell you why this happens >>(I know because I >>was just reading it today :-)) >> >>You are doing this dump on a Live Filesystem. To do >>that use the -L >>option to dump (FreeBSD 5.X or later) which will >>snapshot the filesystem >>first. Either that, or do what we had to do for >>years and drop down to >>single-user mode and make sure no processes are >>running to change the >>filesystem. Dump needs the filesystem to be static. >> >>Then when you restore you will get precisely *one* >>similar "error" (at >>least on 5.4), which I can't explain but can say >>*does not matter*. I >>have restored several such dumps and compared them >>to the original >>filesystem and they are fine. You should do that >>yourself for your own >>peace of mind. (I do similar to you but with gzip >>and on 5.4). >> >>The "error" you'll get should be: >> >> expected next file <inumber>, got <inumber> >> A file that was not listed in the >>directory showed up. >>This can >> occur when using a dump created on an >>active file system. >> >>and I think it must be some artefact of the >>snapshot/dump interaction. >> >>If you use -L and *still* have trouble then it >>sounds like a bug. >> >>--Alex >> >> >> >> >> >> > >I wasn't aware booting off the cd and running fixit >made my filesystems become live... > > It shouldn't, but why are you doing that? Run dump with -L while your laptop is up and running FreeBSD. But while you are in your fixit CD or single-user you could try fscking the filesystems just in case. The output you showed certainly looks like files disappeared between the "dumping directories" and "dumping files" pass. I think that a corrupted filesystem could show that behaviour. Whereas the "error" I consistently get looks like an extra file somehow *appeared* between the passes. >dump -0 -C 32 -f - |bzip2 --best | dd of=/foo/bar.dbz2 > > won't "bzip2 --best > /foo/bar.dbz2" do? Why dd? You might also want -a in the dump command so that there are no "tape size" calculations (or maybe that's the default in 6.X, you'd have to check the man page). Btw, restore also has a -N option which does the restore without actually writing any data. God for seeing if a restore would work but quicker and doesn't require any disk space :-) --Alex
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