Date: Thu, 21 Jul 2005 11:45:33 +0200 From: Marc Olzheim <marcolz@stack.nl> To: freebsd-stable@FreeBSD.org Subject: background fsck, softupdates & inconsistent state on disk Message-ID: <20050721094533.GE52120@stack.nl>
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--7DO5AaGCk89r4vaK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi. Having enough opportunities to do crash recovery with kern/83375 open and some of my services not yet moved back to FreeBSD 4, I noticed that often it crashes just after (or perhaps during) mirroring of a directory tree. The mirroring involves creating a directory with in it 80 subdirectories in it. Now when the machine panics on a 'screen' again, background fsck fails to properly check the filesystem and reports so in /var/log/messages. What I see on that partition is the main directory that should have contained the 80 subdirs, but now it has a link count of 0 and so doesn't even contain a . or .. , let alone the 80 directories that should have been there. The only thing a manual fsck can do after that is unlink the unreferenced inodes and clear up the mess... Shouldn't this be impossible without power loss ? Or is it inherent to SMP that the machine can crash on a process on CPU #0 while CPU #1 is updating disk structures ? Anyway, as soon as the migration of production services suffering from kern/83375 back to 4.x is done I should have a 5.x test machine ready to crash whenever people want, so I can get debug output out of it. If anyone could tell me how to get it and what they need, I'd be happy to provide it. Marc --7DO5AaGCk89r4vaK Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (FreeBSD) iD8DBQFC3269ezjnobFOgrERArKjAKC7MD0AIfrZhthDidHyLYMo6th1HQCcDp3R HhU2UPfgblhFenIqeU+HQ1Q= =uKR+ -----END PGP SIGNATURE----- --7DO5AaGCk89r4vaK--
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