Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 15 Jun 2007 21:50:20 +1000
From:      Peter Jeremy <peterjeremy@optushome.com.au>
To:        Jeremy Chadwick <koitsu@freebsd.org>
Cc:        freebsd-hackers@freebsd.org
Subject:   Re: Disk block or sector to file mapping?
Message-ID:  <20070615115020.GG1173@turion.vk2pj.dyndns.org>
In-Reply-To: <20070614040848.GA30741@eos.sc1.parodius.com>
References:  <4670B27B.6060606@digitalstratum.com> <20070614040848.GA30741@eos.sc1.parodius.com>

next in thread | previous in thread | raw e-mail | index | archive | help

--VrqPEDrXMn8OVzN4
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On 2007-Jun-13 21:08:48 -0700, Jeremy Chadwick <koitsu@freebsd.org> wrote:
>Realistically, what we need on FreeBSD is a tool similar to Solaris's
>format(8) "analyze" command, which does a raw disk scan (r, r/w, and a
>couple other operations).

The "analyze" function is just a pattern test with the ability to
restore the original content.  Writing one is trivial.

>[1] - If the OS is seeing bad blocks on a PATA/SATA disk, usually it means
>that the internal remapping table is full, which means that there were
>other bad blocks on the disk which it has silently remapped for you to
>avoid pain -- and space for those blocks has been exhausted.

Re-mapping generally only works on writes.  If you can't read existing
data off the platter then you will get a bad block error irrespective
of the remapping table.  A sector that could not be read can often be
written.

>and you're stuck simply replacing the disk entirely.  Bad blocks have a
>tendency to spread too...

Definitely - once the number of soft errors starts increasing, it's
time to replace the disk.

--=20
Peter Jeremy

--VrqPEDrXMn8OVzN4
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (FreeBSD)

iD8DBQFGcnz8/opHv/APuIcRAgAvAJ0f+1b7PV2URU337bp24KyHbCCtBwCeMXbv
XoTG5RMH++dBvtZR9bTDESY=
=bApP
-----END PGP SIGNATURE-----

--VrqPEDrXMn8OVzN4--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070615115020.GG1173>