Date: Fri, 10 Jul 2009 00:24:20 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Marcel Moolenaar <xcllnt@mac.com> Cc: freebsd-geom@freebsd.org Subject: Re: glabel and real disk IDs Message-ID: <20090709222420.GE2438@garage.freebsd.pl> In-Reply-To: <C3B56501-1F02-42FC-B848-DD3969965E82@mac.com> References: <h34lml$6fv$1@ger.gmane.org> <20090709200102.GA2438@garage.freebsd.pl> <C3B56501-1F02-42FC-B848-DD3969965E82@mac.com>
next in thread | previous in thread | raw e-mail | index | archive | help
--8vCeF2GUdMpe9ZbK Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 09, 2009 at 02:32:59PM -0700, Marcel Moolenaar wrote: >=20 > On Jul 9, 2009, at 1:01 PM, Pawel Jakub Dawidek wrote: >=20 > > > >>The purpose of this would be to have a unique disk ID without =20 > >>explicitly > >>setting a label (e.g. as is commonly advised for ZFS and drive =20 > >>swapping). > > > >I guess you advice that? There is no such need when it comes to ZFS. =20 > >ZFS > >can find his components just fine without using their names. Disk IDs > >were added for ZFS in the past, but now they serve no purpose, I'd > >prefer to remove them altogether or just leave them for informational > >purpose as they exist now. >=20 > Just as an FYI: >=20 > I see ZFS getting confused when disks are shuffled around. > The confusion is the result of having device paths stored > in the ZFS label match the device name of some other vdev > that part of the same pool. >=20 > Replacing a device with itself doesn't help, because ZFS > complains that the vdev is part of an active pool in that > case. It seems that only labels will work here... Solaris is using device names stored in ZFS label and if this is not the drive it was looking for, it is doing ID-to-path translation to find new path name. On FreeBSD on the other hand (after upgrade to v13) I gave up doing similar thing because disk IDs weren't available from all disk device drivers (I implemented it for ATA and I received no help with other drivers). Currently the idea is to just go through all GEOM providers looking for proper ZFS metadata (think of it as manual tasting), so even if device name changes, ZFS should be able to locate it. If there are still problems locating the disk, there simply might be a bug in the code of some sort. --=20 Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! --8vCeF2GUdMpe9ZbK Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFKVm4UForvXbEpPzQRAgp1AJ4i4vO8MFGJoJjFAFlMFfdx+C1sAQCfdjmV ItDVphnCZaHfRLTpq8UMxTo= =N+uU -----END PGP SIGNATURE----- --8vCeF2GUdMpe9ZbK--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20090709222420.GE2438>