From owner-freebsd-fs@FreeBSD.ORG Mon Nov 1 08:28:08 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 486F7106566B for ; Mon, 1 Nov 2010 08:28:08 +0000 (UTC) (envelope-from pjd@garage.freebsd.pl) Received: from mail.garage.freebsd.pl (60.wheelsystems.com [83.12.187.60]) by mx1.freebsd.org (Postfix) with ESMTP id E5C6C8FC14 for ; Mon, 1 Nov 2010 08:27:58 +0000 (UTC) Received: by mail.garage.freebsd.pl (Postfix, from userid 65534) id AFFF945C9C; Mon, 1 Nov 2010 09:27:56 +0100 (CET) Received: from localhost (chello089073192049.chello.pl [89.73.192.49]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.garage.freebsd.pl (Postfix) with ESMTP id DF4D345B36; Mon, 1 Nov 2010 09:27:50 +0100 (CET) Date: Mon, 1 Nov 2010 09:27:11 +0100 From: Pawel Jakub Dawidek To: "James R. Van Artsdalen" Message-ID: <20101101082711.GG2160@garage.freebsd.pl> References: <20101031104209.771cc47e@r500.local> <4CCDB360.50609@jrv.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9Iq5ULCa7nGtWwZS" Content-Disposition: inline In-Reply-To: <4CCDB360.50609@jrv.org> User-Agent: Mutt/1.4.2.3i X-PGP-Key-URL: http://people.freebsd.org/~pjd/pjd.asc X-OS: FreeBSD 9.0-CURRENT amd64 X-Spam-Checker-Version: SpamAssassin 3.0.4 (2005-06-05) on mail.garage.freebsd.pl X-Spam-Level: X-Spam-Status: No, score=-0.6 required=4.5 tests=BAYES_00,RCVD_IN_SORBS_DUL autolearn=no version=3.0.4 Cc: freebsd-fs@freebsd.org Subject: Re: ZFS inresponsive. X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Nov 2010 08:28:08 -0000 --9Iq5ULCa7nGtWwZS Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Oct 31, 2010 at 01:20:16PM -0500, James R. Van Artsdalen wrote: > Thomas Zander wrote: > > Same here, same setup. ZFS, GELI, USB. >=20 > It is not a good idea to use USB disks with ZFS. It can cause pool loss. >=20 > Many (most?) USB enclosures use USB<->SATA chips that discard the > SYNC/FLUSH command to the disk. As a result this opens a window of time > where disk writes might be reordered in a way that cause the ZFS > structures to become corrupted. There's no problem in normal operation > but there may be a failure if there is a power loss. >=20 > The log entries in Fabian's note look like a USB SYNC/FLASH failure to > me - that USB enclosure should not be used with ZFS. >=20 > At one time there was talk of "deferred reallocation" in ZFS which would > deal with broken USB enclosures but I don't know if Sun ever got around > to this. Yes, it is implemented in new ZFS. Blocks are not reused for next three transaction groups and one can import a pool by falling back to the last working transaction group if the most recent one is corrupted. --=20 Pawel Jakub Dawidek http://www.wheelsystems.com pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --9Iq5ULCa7nGtWwZS Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.14 (FreeBSD) iEYEARECAAYFAkzOed8ACgkQForvXbEpPzRjrwCg6vBC8ojXRxBCrM+nWIyBmWRa UScAoK+tDi2QjskEOXN+I4M3FDVOURA1 =yllR -----END PGP SIGNATURE----- --9Iq5ULCa7nGtWwZS--