Date: Mon, 6 Apr 2009 22:20:21 +0200 From: Roland Smith <rsmith@xs4all.nl> To: John Almberg <jalmberg@identry.com> Cc: freebsd-questions@freebsd.org Subject: Re: how to recover after power outage Message-ID: <20090406202021.GA25679@slackbox.xs4all.nl> In-Reply-To: <C0C930E7-A989-4606-A516-040A2F894841@identry.com> References: <AF401DB4-C4D1-44B0-B9D2-A34D81596481@identry.com> <4ad871310904050141k11eda14vd8db9224f4384757@mail.gmail.com> <1ED100F1-51AE-478D-873C-40FF43EA17FB@identry.com> <gra0pd$tph$1@ger.gmane.org> <B695560F-1ED1-45F2-AEB2-2268045A01AC@identry.com> <gras5o$50f$1@ger.gmane.org> <EFC6BC14-1BCB-48F4-BB54-12F1A12663D9@identry.com> <C0C930E7-A989-4606-A516-040A2F894841@identry.com>
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--sm4nu43k4a2Rpi4c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Apr 06, 2009 at 02:08:18PM -0400, John Almberg wrote: <snip>=20 > Okay, so my new database server is running with backup data and I am =20 > trying to salvage the old database, or what's left of it. >=20 > Unfortunately, it seems like what's left of it, is not much. >=20 > the /var/db/mysql directory tree is now a file: >=20 > qu# ls -l /var/db/mysql > -rwx------ 2 mysql wheel 1024 Jul 5 2008 /var/db/mysql Normally it shouldn't be possible to turn a directory into a file. Using open(2) to create a file that already exists as a directory should result in an error. > The situation looks hopeless to me. Is it? It might not be. Unless the data was actively wiped or overwritten, the data is probably still there on the disk in unallocated sectors. Forensic analysis programs like the sleuth kit [http://www.sleuthkit.org/sleuthkit/desc.php] _might_ be able to get some of the data back. But don't hold you breath. It's practically impossible to get data back from a modern drive once it has been overwritte= n. > Another question: given that the file system took a major hit, should =20 > I try to fix it, or just do a clean install? I'm leaning towards the =20 > clean install since I've been meaning to upgrade this machine to 7.1 =20 > anyway. I would advise you to make a copy of the disk contents with dd, so you can poke around in it at your leisure. Then check the disk with e.g. smartmontools or the tools provided by the manufacturer and to a clean install. > Is there anyway to fix the file system, reliably? fsck doesn't seem =20 > to be able to solve all the problems. Is that with fsck_ffs running in preen mode? If so, try it without the -p option. If that doesn't work you might contemplate using the -D option, but this can be dangerous; see fsck_ffs(8). If fsck_ffs even then cannot repair the damage, there's not much you can do except wipe the disk and reinstall. Also, check for loose (S)ATA cables. This can cause g_vfs_done errors while the disk is fine. If there are no obvious errors of that kind I'd be extra suspicious about disk hardware failure. If the drive is still in warranty, I'd have it replaced. If not, you might still think about replacing it. buying a new disk is almost certainly cheaper that trawling through a diskload of data trying to make sense of it... Roland --=20 R.F.Smith http://www.xs4all.nl/~rsmith/ [plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated] pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725) --sm4nu43k4a2Rpi4c Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (FreeBSD) iEYEARECAAYFAknaZAUACgkQEnfvsMMhpyUKmwCggkWLgJo9OcLXq3ibzEdbE7A2 jNwAn3TIWE6fc4ZNxgRfZmySHtkPkuL1 =M65I -----END PGP SIGNATURE----- --sm4nu43k4a2Rpi4c--
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