Date: Mon, 12 Oct 2009 09:44:04 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-geom@freebsd.org Subject: Re: Virstor provider lost metadata. Rescue possible? Message-ID: <haumoj$fnh$1@ger.gmane.org> In-Reply-To: <469001.5449.qm@web28202.mail.ukl.yahoo.com> References: <469001.5449.qm@web28202.mail.ukl.yahoo.com>
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This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigD92C6DEDD556D736A1389FD6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Frank Beckmann wrote: > Hello, >=20 > one of my virstor providers lost its metadata. It looks like the sector= got filled with random data. it is the second last filled sector in that= virstor. Executing the command "gvirstor list", "gvirstor status" or "sy= sctl -a" resulted in a kernel panic. >=20 > I handcrafted the destroyed sector assuming that all chunks of that pro= vider were used and setting the flags to 0. Now the kernel doesn't panic = anymore but I get the error message: >=20 > GEOM_VIRSTOR[1]: virstor_check_and_run: Invalid entry 100542 in map for= vs3 > GEOM_VIRSTOR[1]: virstor_check_and_run: provider_no: 25, n_components: = 33 provider_chunk: 512, chunk_count 512 >=20 > Provider 25 is the one which lost its metadata. >=20 > The version of FreeBSD is: 7.2-RC1 >=20 > Is it possible to revive that virstor to rescue some of its data? This is a serious problem, but as long as the first component of the virstor is alive and, as you say, only the metadata is damaged on component 25 (of 33), there is a chance. It looks like chunk_count is wrong for provider 25 - it holds the number of chunks (of default 4 MiB) on the device. You could calculate device_size/4194304 and write it in the chunk_count field of the reconstructed metadata - see if that helps (reference /sys/geom/virstor/g_virstor_md.h). You should make a backup of the first couple of chunks on the first components (the actual number depends on your virstor virtual size - 16 MiB should be enough for most) and the metadata of all other components before experimenting like this. Do you have any idea how the metadata got damaged? --------------enigD92C6DEDD556D736A1389FD6 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/ iEYEARECAAYFAkrS3kQACgkQldnAQVacBcizZgCgmxn0cEDlkW8063rIqCCj+bP6 ZDoAoOTCPrkb6HVHi5a7oZlFNedlMBay =mG1A -----END PGP SIGNATURE----- --------------enigD92C6DEDD556D736A1389FD6--
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