From owner-freebsd-current@FreeBSD.ORG Fri Oct 17 17:54:28 2008 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 66C4410656B5 for ; Fri, 17 Oct 2008 17:54:28 +0000 (UTC) (envelope-from scode@hyperion.scode.org) Received: from hyperion.scode.org (cl-1361.ams-04.nl.sixxs.net [IPv6:2001:960:2:550::2]) by mx1.freebsd.org (Postfix) with ESMTP id 265B98FC31 for ; Fri, 17 Oct 2008 17:54:27 +0000 (UTC) (envelope-from scode@hyperion.scode.org) Received: by hyperion.scode.org (Postfix, from userid 1001) id 83D9E23C431; Fri, 17 Oct 2008 19:54:25 +0200 (CEST) Date: Fri, 17 Oct 2008 19:54:25 +0200 From: Peter Schuller To: Zaphod Beeblebrox Message-ID: <20081017175424.GA73168@hyperion.scode.org> References: <0A8710FF880BBB4687AEC66F9DCF7D0C26B462@SERVER1.emerytelcom.com> <5f67a8c40810142200o6074cd42hec0ff6f2b87d3648@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Dxnq1zWXvFF0Q93v" Content-Disposition: inline In-Reply-To: <5f67a8c40810142200o6074cd42hec0ff6f2b87d3648@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: freebsd-current@freebsd.org, Daniel Jameson Subject: Re: ZFS attaching direct access drives as Scsibus#target#drive# X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Oct 2008 17:54:28 -0000 --Dxnq1zWXvFF0Q93v Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > glabel can have some funny effects due to the geom taste order. If > something is part of a mirror (for instance) and the label tastes before = the > mirror, I've seen items of the mirror come up with glabel instead of > attaching to the mirror. Does gmirror perhaps keep meta-data at the beginning of the underlying device? Something which can easily happen is that you have, for example, a slice covering the entire device (exactly the entire device). You then glabel the slice, and when you reboot the underlying device is labeled instead of the slice. Similar issues can happen in other cases, such as glabel:ing an iSCSI target on another host, if that iSCSI target is backed by, for example, a zvol.=20 For these reasons I always make sure that the "contained" device ends earlier than the "containing" device (and the other way around). This way there is never any GEOM (disk, slice, partition, glabel, gmirror, etc) which starts or ends at the exact same spot as another GEOM. This removes the ambiguity. At least this is my interpretation of the situation; I haven't gone and proven it. --=20 / Peter Schuller PGP userID: 0xE9758B7D or 'Peter Schuller ' Key retrieval: Send an E-Mail to getpgpkey@scode.org E-Mail: peter.schuller@infidyne.com Web: http://www.scode.org --Dxnq1zWXvFF0Q93v Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) iEYEARECAAYFAkj40VAACgkQDNor2+l1i30tEQCgs4QOonDK6T0s1aF9lk3MNVxd RwMAnit0ukyHXLiq6qskT6J8+mSHpUI4 =giPQ -----END PGP SIGNATURE----- --Dxnq1zWXvFF0Q93v--