From: Alan McKinnon <alan.mckinnon@gmail.com>
To: gentoo-user@lists.gentoo.org
Subject: Re: [gentoo-user] Re: OT: Fighting bit rot
Date: Wed, 9 Jan 2013 01:37:26 +0200 [thread overview]
Message-ID: <20130109013726.4016dda2@khamul.example.com> (raw)
In-Reply-To: <kci5pj$rt5$1@ger.gmane.org>
On Tue, 8 Jan 2013 22:15:15 +0000 (UTC)
Grant Edwards <grant.b.edwards@gmail.com> wrote:
> IMO, having backup data _is_ very valuable, but regularly reading
> files and comparing them to backup copies isn't a useful way to detect
> failing media.
He doesn't suggest you compare the live data to a backup. He suggests
you compare the current checksum to the last known (presumed or
verified as good) checksum, and if they are different then deal with it.
"deal with it" likely involves a restore after some kind of verify
process.
I agree that comparing current data with a backup is pretty pointless -
you don't know which is the bad one if they differ.
ZFS is designed to deal with this problem by checksumming fs blocks
continually; it does this at the filesystem level, not at the disk
firmware level. Pity about the license incompatibility, it's a great fs.
--
Alan McKinnon
alan.mckinnon@gmail.com
next prev parent reply other threads:[~2013-01-08 23:43 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-07 20:11 [gentoo-user] OT: Fighting bit rot Florian Philipp
2013-01-07 21:07 ` Paul Hartman
2013-01-07 22:05 ` Florian Philipp
2013-01-07 21:33 ` Michael Mol
2013-01-07 22:10 ` Florian Philipp
2013-01-07 23:20 ` Alan McKinnon
2013-01-08 7:27 ` Florian Philipp
2013-01-08 7:55 ` Alan McKinnon
2013-01-08 16:16 ` Florian Philipp
2013-01-08 16:42 ` Alan McKinnon
2013-01-08 17:41 ` Pandu Poluan
2013-01-08 19:02 ` Florian Philipp
2013-01-09 2:55 ` Pandu Poluan
2013-01-08 19:53 ` [gentoo-user] " Grant Edwards
2013-01-08 20:30 ` Florian Philipp
2013-01-08 21:45 ` Alan McKinnon
2013-01-08 22:15 ` Grant Edwards
2013-01-08 23:37 ` Alan McKinnon [this message]
2013-01-09 2:47 ` Grant Edwards
2013-01-09 8:31 ` Alan McKinnon
2013-01-09 14:48 ` Grant Edwards
2013-01-09 15:36 ` Holger Hoffstaette
2013-01-09 16:32 ` Pandu Poluan
2013-01-09 16:42 ` Grant Edwards
2013-01-09 20:52 ` Alan McKinnon
2013-01-09 20:53 ` Alan McKinnon
2013-01-08 15:29 ` Grant Edwards
2013-01-08 15:42 ` Michael Mol
2013-01-08 16:28 ` Florian Philipp
2013-01-08 17:35 ` [gentoo-user] " Volker Armin Hemmann
2013-01-08 19:06 ` Florian Philipp
2013-01-08 20:57 ` Joshua Murphy
2013-01-08 21:49 ` Alan McKinnon
2013-01-08 19:11 ` [gentoo-user] " James
2013-01-09 4:40 ` Volker Armin Hemmann
2013-01-09 15:17 ` walt
2013-01-09 18:57 ` Volker Armin Hemmann
2013-01-09 0:12 ` [gentoo-user] " Randy Barlow
2013-01-07 23:31 ` William Kenworthy
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