Date: Tue, 6 Jan 2004 14:29:45 +0300 From: Sergey 'DoubleF' Zaharchenko <doublef@tele-kom.ru> To: Malcolm Kay <malcolm.kay@internode.on.net> Cc: FreeBSD <freebsd-questions@freebsd.org> Subject: Re: "Cannot find file system superblock" error - how to recover? Message-ID: <20040106142945.0d90c530.doublef@tele-kom.ru> In-Reply-To: <200401061943.44734.malcolm.kay@internode.on.net> References: <20040106002948.38813.qmail@web41102.mail.yahoo.com> <200401061329.26665.malcolm.kay@internode.on.net> <20040106073519.54620420.doublef@tele-kom.ru> <200401061943.44734.malcolm.kay@internode.on.net>
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--Signature=_Tue__6_Jan_2004_14_29_45_+0300_fnGhIlCWL0kb=sJt Content-Type: text/plain; charset=US-ASCII Content-Disposition: inline Content-Transfer-Encoding: 7bit On Tue, 6 Jan 2004 19:43:44 +1030 Malcolm Kay <malcolm.kay@internode.on.net> probably wrote: > On Tue, 6 Jan 2004 15:05, Sergey 'DoubleF' Zaharchenko wrote: > > On Tue, 6 Jan 2004 13:29:26 +1030 > > > > Malcolm Kay <malcolm.kay@internode.on.net> probably wrote: > > > On Tue, 6 Jan 2004 10:59, Scott I. Remick wrote: > > > > Sorry for the delay... holidays had me busy. > > > > Me too:) > > > > > > Hopefully you're still around > > > > and interested in picking up where we left off. I think we're > > > > definitely onto something... > > > > > > Looking back over some of your e-mails I find: > > > QUOTE > > > su-2.05b# disklabel -r /dev/ad6s1c > > > # /dev/ad6s1c: > > > 8 partitions: > > > # size offset fstype [fsize bsize bps/cpg] > > > c: 156344517 63 unused 0 0 # "raw" part, > > > don't edit > > > e: 156344517 63 4.2BSD 2048 16384 89 > > > partition c: partition extends past end of unit > > > disklabel: partition c doesn't start at 0! > > > disklabel: An incorrect partition c may cause problems for standard > > > system utilities > > > partition e: partition extends past end of unit > > > > > > That doesn't look good. > > > ENDQUOTE > > > > > > The 63 offset is spurious. I've seen this before somewhere but can't > > > remember the details -- i.e the value 63. > > > > I know where you've seen this. The normal offset for the first *slice* > > is 63 sectors, for some historical reasons (those extra sectors were to > > be used for bad block replacement or something like that). > > > > Yes, I expect it in the output from fdisk. > Ignoring for the moment that the BIOS ideas of geometry has nothing > to do with the physical reality; all slices start at sector 1 of a track so having > used sector 1 of the first track (cylinder 0 head 0) for the MBR, the first slice > must start at cylinder 0 head 1 sector 1; usually an offset of 63 with the assumed > virtual geometry. > (Nothing to do with bad block replacement which on modern drives is almost > completely hidden) Yes I know, I meant used to be used for:) > But I have seen the 63 before in corrupted disklabels, not just slice positions. Maybe in dedicated disklabels? How did they get *that* corrupted? > > Not sure how the 63 made it into the disklabel, though. > > Neither do I. > > Malcolm Kay > > -- DoubleF You look like a million dollars. All green and wrinkled. --Signature=_Tue__6_Jan_2004_14_29_45_+0300_fnGhIlCWL0kb=sJt Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (FreeBSD) iD8DBQE/+pw2wo7hT/9lVdwRAnyOAKCCihKdE3Q057qgfRmoRbeqPj1AuACeOklz 5tmtkPX9b2pFCR+1Ygg8enw= =XGz4 -----END PGP SIGNATURE----- --Signature=_Tue__6_Jan_2004_14_29_45_+0300_fnGhIlCWL0kb=sJt--
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