Date: Mon, 25 May 2009 01:24:09 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-current@freebsd.org Subject: Re: ZFS panic under extreme circumstances (2/3 disks corrupted) Message-ID: <gvckuv$u9l$1@ger.gmane.org> In-Reply-To: <4FE794E9-075D-4563-B395-BD5E459937DF@exscape.org> References: <4E6E325D-BB18-4478-BCFD-633D6F4CFD88@exscape.org> <4FE794E9-075D-4563-B395-BD5E459937DF@exscape.org>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig5E56879B976C42ACDC76D810 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Thomas Backman wrote: >=20 > On May 24, 2009, at 09:02 PM, Thomas Backman wrote: >=20 >> So, I was playing around with RAID-Z and self-healing, when I decided >> to take it another step and corrupt the data on *two* disks (well, >> files via ggate) and see what happened. I obviously expected the pool >> to go offline, but I didn't expect a kernel panic to follow! >> >> What I did was something resembling: >> 1) create three 100MB files, ggatel create to create GEOM providers >> from them >> 2) zpool create test raidz ggate{1..3} >> 3) create a 100MB file inside the pool, md5 the file >> 4) overwrite 10~20MB (IIRC) of disk2 with /dev/random, with dd >> if=3D/dev/random of=3D./disk2 bs=3D1000k count=3D20 skip=3D40, or so (= I now know >> that I wanted *seek*, not *skip*, but it still shouldn't panic!) >> 5) Check if the md5 of file: everything OK, zpool status shows a >> degraded pool. >> 6) Repeat step #4, but with disk 3. >> 7) zpool scrub test >> 8) Panic! >> [...] > FWIW, I couldn't replicate this when using seek (i.e. corrupt the middl= e > of the "disk" rather than the beginning): Did you account for the time factor? Between your steps 5 and 6, wouldn't ZFS automatically begin data repair? --------------enig5E56879B976C42ACDC76D810 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkoZ1xkACgkQldnAQVacBcjfDgCdFFCS5a1RaWeHHD20TDRtJmxa zXsAoNsliQ36Ar65p5+62tMUoHTjcOzE =x3np -----END PGP SIGNATURE----- --------------enig5E56879B976C42ACDC76D810--
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