From: Helge Hafting <helgehaf@aitel.hist.no>
To: Valdis.Kletnieks@vt.edu
Cc: linux-kernel@vger.kernel.org
Subject: Re: Are linux-fs's drive-fault-tolerant by concept?
Date: Sun, 20 Apr 2003 12:51:54 +0200 [thread overview]
Message-ID: <20030420105154.GA16451@hh.idb.hist.no> (raw)
In-Reply-To: <200304192115.h3JLFVuL018983@turing-police.cc.vt.edu>
On Sat, Apr 19, 2003 at 05:15:31PM -0400, Valdis.Kletnieks@vt.edu wrote:
> On Sat, 19 Apr 2003 22:56:21 +0200, Helge Hafting said:
>
> > There are commercially available programs that guarantees to
> > wipe your drive clean - including hidden areas and remapped
> > sectors. You should then be able to send drives
> > back for warranty replacement.
>
> These don't address the problem - if the drive won't go "ready" because
> of a blown server platter, your data won't get overwritten but it's still
> readable (a number of companies make good money at this).
>
I see. Your data is so special that you expect people to pay for
reconstruction hoping to find something that pays for all
that trouble and more.
> In general, if the disk is dead enough that you're looking at replacement,
> you'll probably not be totally pleased with the results of those programs..
>
I have replaced a couple of drives in my life - because a few sectors
didn't read back right. I expect a overwrite program to be just
fine under such circumstances.
> > There are also bulk erasers that reset every bit magnetically,
> > but those will probably void the warranty too. (You'll
> > need a low-level reformat to recreate sector addresses on the
> > suddenly blank surface.)
>
> Note that this only works well for single-platter disks - the field
> you need to get the *inner* surfaces of the platters, especially for
> a 5 or 6 platter disk, is quite astounding....
Why would it be hard to reach the inner surfaces - the disks
are not superconducting so the outer ones do not shield the
inner ones from a strong magnetic field. You should be fine
as long as the field extend far enough to get the entire
drive. A high-frequency device might have trouble,
but you don't need that - even a static field will do.
Helge Hafting
next prev parent reply other threads:[~2003-04-20 10:38 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-19 16:04 Are linux-fs's drive-fault-tolerant by concept? Stephan von Krawczynski
2003-04-19 15:29 ` Alan Cox
2003-04-19 17:00 ` Stephan von Krawczynski
2003-04-19 22:04 ` Alan Cox
2003-04-20 16:24 ` Stephan von Krawczynski
2003-04-20 13:59 ` John Bradford
2003-04-20 16:55 ` Stephan von Krawczynski
2003-04-20 17:12 ` John Bradford
2003-04-20 17:21 ` Stephan von Krawczynski
2003-04-20 18:48 ` Alan Cox
2003-04-20 20:00 ` John Bradford
2003-04-21 1:51 ` jw schultz
2003-04-19 21:13 ` Jos Hulzink
2003-04-20 16:07 ` Stephan von Krawczynski
2003-04-20 16:40 ` John Bradford
2003-04-20 17:01 ` Stephan von Krawczynski
2003-04-20 17:20 ` John Bradford
2003-04-21 9:32 ` Stephan von Krawczynski
2003-04-21 9:55 ` John Bradford
2003-04-21 11:24 ` Stephan von Krawczynski
2003-04-21 11:50 ` Alan Cox
2003-04-21 12:14 ` John Bradford
2003-04-19 16:22 ` John Bradford
2003-04-19 16:36 ` Russell King
2003-04-19 16:45 ` John Bradford
2003-04-19 16:52 ` Stephan von Krawczynski
2003-04-19 20:04 ` John Bradford
2003-04-19 20:33 ` Andreas Dilger
2003-04-21 9:25 ` Denis Vlasenko
2003-04-21 9:42 ` John Bradford
2003-04-21 10:25 ` Stephan von Krawczynski
2003-04-21 10:50 ` John Bradford
2003-04-19 20:38 ` Stephan von Krawczynski
2003-04-20 14:21 ` John Bradford
2003-04-21 9:09 ` Denis Vlasenko
2003-04-21 9:35 ` John Bradford
2003-04-21 11:03 ` Stephan von Krawczynski
2003-04-21 12:04 ` John Bradford
2003-04-21 11:22 ` Denis Vlasenko
2003-04-21 11:46 ` Stephan von Krawczynski
2003-04-21 12:13 ` John Bradford
2003-04-19 20:05 ` John Bradford
2003-04-19 23:13 ` Arnaldo Carvalho de Melo
2003-04-19 17:54 ` Felipe Alfaro Solana
2003-04-25 0:07 ` Stewart Smith
2003-04-25 0:52 ` Richard B. Johnson
2003-04-25 7:13 ` John Bradford
[not found] ` <20030419161011$0136@gated-at.bofh.it>
2003-04-19 17:18 ` Florian Weimer
2003-04-19 18:07 ` Stephan von Krawczynski
2003-04-19 18:41 ` Dr. David Alan Gilbert
2003-04-19 20:56 ` Helge Hafting
2003-04-19 21:15 ` Valdis.Kletnieks
2003-04-20 10:51 ` Helge Hafting [this message]
2003-04-20 19:04 ` Valdis.Kletnieks
2003-04-19 21:57 ` Alan Cox
2003-04-20 10:09 ` Geert Uytterhoeven
2003-04-21 8:37 ` Denis Vlasenko
2003-05-05 12:38 ` Pavel Machek
2003-04-19 22:02 ` Alan Cox
2003-04-20 8:41 ` Arjan van de Ven
2003-04-25 0:11 ` Stewart Smith
2003-04-20 15:06 Chuck Ebbert
2003-04-20 15:19 ` John Bradford
2003-04-20 17:03 Chuck Ebbert
2003-04-20 17:25 ` John Bradford
2003-04-20 17:28 Chuck Ebbert
2003-04-21 9:36 ` Stephan von Krawczynski
2003-04-20 17:28 Chuck Ebbert
2003-04-20 17:44 Chuck Ebbert
2003-04-20 17:44 Chuck Ebbert
[not found] <mail.linux.kernel/20030420185512.763df745.skraw@ithnet.com>
[not found] ` <03Apr21.020150edt.41463@gpu.utcc.utoronto.ca>
2003-04-21 11:19 ` Stephan von Krawczynski
2003-04-21 11:52 ` Alan Cox
2003-04-21 14:14 ` Valdis.Kletnieks
2003-05-06 7:03 ` Mike Fedyk
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