Date: Wed, 02 Sep 2009 10:49:05 +0200 From: Mark Stapper <stark@mapper.nl> To: Thomas Backman <serenity@exscape.org> Cc: freebsd-stable@freebsd.org, Emil Mikulic <emikulic@gmail.com>, Miroslav Lachman <000.fbsd@quip.cz>, Maciej Jan Broniarz <gausus@gausus.net> Subject: Re: zfs on gmirror slice Message-ID: <4A9E3181.9030601@mapper.nl> In-Reply-To: <DB79F60C-1F6F-4605-A39C-F916E20796B4@exscape.org> References: <a7454e2f0909010704g2fb27216hacb3ffd2cae5594c@mail.gmail.com> <061541E3-F301-46C4-8ECB-5B05854F0EAA@exscape.org> <a7454e2f0909010904s224be2ectdd18eb887f4c1311@mail.gmail.com> <4A9D558A.9070609@quip.cz> <4A9E1CB5.6030906@mapper.nl> <20090902074445.GA13588@dmr.ath.cx> <4A9E2C7C.6030904@mapper.nl> <DB79F60C-1F6F-4605-A39C-F916E20796B4@exscape.org>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig1730779D28C2B6405EFF9CF4 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thomas Backman wrote: > On Sep 2, 2009, at 10:27 AM, Mark Stapper wrote: > >> > Nothing a LiveCD or something to that regard can't handle. Obviously > this doesn't work for everyone, but it should for many. Actually it won't because updating zfs comes with updating your world. After updating you world, you will be running a newer ZFS version then the one that come with the RELEASE install, hence the need to update your zfs filesystems. Incidentally, the livefs CD contains the "old" zfs version. You see where I'm going? You could, of course, copy the base system to a USB drive, boot from it, and so sidestep the whole "can't unmount root" problem, but it's hard to insert a USB device over ssh... ... ... >> self-healing sounds very nice, but with mirrorring you have data on tw= o >> discs, so in that case there no "healing" involved, it's just >> checksumming and reading the non-corrupted copy. >> From the gmirror manpage: "All operations like failure detection, stal= e >> component detection, rebuild of stale components, etc. are also done >> automatically." >> This would indicate the same functionality, with a much less fancy nam= e. >> However, i have not tested it the way they demonstrate zfs's >> "self-healing" property. >> I might, if I get the time to run it in a virtual machine one of these= >> days.. > If ZFS finds a corrupted copy and a non-corrupted one in a mirrored > ZFS pool, it will repair the damage so that both copies are valid, so > yes, self-healing will indeed occur. :) I'm feeling Shakespearean again... My point was that I find "self-healing" too magic sounding. While indeed it means:"Automatic data error detection and rebuilding" or something along those lines. We don't call the automatic remapping of bad sectors in HDD's "self-healing" do we= ? Alas, I must admit that on file-system level, some "healing" does take place. --------------enig1730779D28C2B6405EFF9CF4 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/ iEYEARECAAYFAkqeMYMACgkQN9xNqOOVnWCNywCfa3vC2xSWQI/l0aPmYfxqD4hS mUsAoJYAij0rOeRTvApvaEKm6irTGrJ0 =6FGh -----END PGP SIGNATURE----- --------------enig1730779D28C2B6405EFF9CF4--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4A9E3181.9030601>