From owner-freebsd-fs@FreeBSD.ORG Tue Jan 29 15:45:12 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 0EC92475 for ; Tue, 29 Jan 2013 15:45:12 +0000 (UTC) (envelope-from romain@blogreen.org) Received: from marvin.blogreen.org (unknown [IPv6:2001:470:1f12:b9c::2]) by mx1.freebsd.org (Postfix) with ESMTP id B822231C for ; Tue, 29 Jan 2013 15:45:11 +0000 (UTC) Received: by marvin.blogreen.org (Postfix, from userid 1001) id 57AE31B1C1; Tue, 29 Jan 2013 16:45:07 +0100 (CET) Date: Tue, 29 Jan 2013 16:45:07 +0100 From: Romain =?iso-8859-1?Q?Tarti=E8re?= To: freebsd-fs@freebsd.org Subject: Re: ZFS deduplication Message-ID: <20130129154507.GA53833@blogreen.org> References: <20130123143728.GA84218@blogreen.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="pWyiEgJYm5f9v55/" Content-Disposition: inline In-Reply-To: <20130123143728.GA84218@blogreen.org> X-PGP-Key: http://romain.blogreen.org/pubkey.asc User-Agent: Mutt/1.5.21 (2010-09-15) X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 29 Jan 2013 15:45:12 -0000 --pWyiEgJYm5f9v55/ Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jan 23, 2013 at 03:37:29PM +0100, Romain Tarti=E8re wrote: > However, `zpool list` reports an inconsistent deduplication value (it > used to be ~1.4 AFAICR): >=20 > > zpool list data > > NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT > > data 460G 101G 359G 21% 1386985.39x ONLINE - Looks like this was some kind of corruption: the system crashed (it has crashed a few times over the last few months but I could not get details because of a failing serial port on the machine and the X server was running) and was then unable to reboot: just after importing the zpool, the kernel panicked in ddt_phys_decref() trying to dereference a NULL pointer (because of the serial port I don't have a text backtrace, however I took a few shots just in case). I replaced the disks of the pool with new ones, reinstalled FreeBSD and restored from backup. I keep the old disks untouched in case some FreeBSD developer involved in ZFS is interested about this corruption and needs a real-life corrupted filesystem for analysis. Please let me know by private mail. Thanks, Romain --=20 Romain Tarti=E8re http://people.FreeBSD.org/~romain/ pgp: 8234 9A78 E7C0 B807 0B59 80FF BA4D 1D95 5112 336F (ID: 0x5112336F) (plain text =3Dnon-HTML=3D PGP/GPG encrypted/signed e-mail much appreciated) --pWyiEgJYm5f9v55/ Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iQGcBAEBAgAGBQJRB+6DAAoJELpNHZVREjNvuiwMAI9c94X5rN00GgKkPbPdF9KX WlOv67UEXrdN6GfsjKXEnC9BTPOCGjs3ZCw3esllQqyJEoUL+nzZVyxU9IrLdVPA v9AHX523u8d1SqpsGZKnhCd+JWWMuOa6CXK5GgoVtSajxZXurt1CSpXnyRw6yxQZ PDM8oPXWMbtT+mx+AJseZKyAF2TSDDkYCoKVx1NaaZFAWwVZw4cFpBZHcvGrzvHh SqLsiYnSAJ5watETrowrNZrpOK75EKOVDaPCpTesvY+Yhzu2gKMeOIlyNqYodssT j9ezEKjYNYFkFMXxvUS9QP0BtIOUq/O4rd42Bu6HwzX8WCoe9Dyj1iIr8X+/A65o DP4zVSIW6u3y4haEd0ZmhZNUid4S1vsBixiYSKc8B69uqkzmDgYrruCoTFOKzlFB h5BmB1JpGa2tml8Kq18+3+KEmEAgyY+Qy6AF4rdXvpfizUibATKg1Lvh94uZSq+O 2cZZRvLu4nfcT7AuA+/BvFdns9Cwz1ampM4RHGEfdQ== =7M8k -----END PGP SIGNATURE----- --pWyiEgJYm5f9v55/--