Date: Sun, 19 Dec 2004 02:31:59 +0100 From: Christian Hiris <4711@chello.at> To: freebsd-questions@freebsd.org Cc: wbwither@bobball.uchicago.edu Subject: Re: Identical hard drives, different disklabel sectors/cylinders Message-ID: <200412190232.15663.4711@chello.at> In-Reply-To: <20041218233156.GA10895@bobball.uchicago.edu> References: <20041218233156.GA10895@bobball.uchicago.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On Sunday 19 December 2004 00:31, wbwither@bobball.uchicago.edu wrote:
> Hi all,
>
> I've got a problem question about my hard drives. I've installed
> two brand-new Western Digital 250GB drives on the same channel of
> a Maxtor-branded PCI/IDE controller (Promise chipset). I've tried
> different channels, different cables, and using the motherboard's
> IDE controller -- same thing every time. Here's from
> /var/log/messages:
>
> Dec 18 15:59:23 /kernel: ad4: 238475MB <WDC WD2500SB-01KBA0>
> [484521/16/63] at ata2-master UDMA100 Dec 18 15:59:23 /kernel: ad5:
> 238475MB <WDC WD2500SB-01KBA0> [484521/16/63] at ata2-slave UDMA100
>
> So you can see it's identifying them the same at startup. Now:
>
> su-2.05b# disklabel ad4
> # /dev/ad4c:
> bytes/sector: 512
> sectors/track: 63
> tracks/cylinder: 255
> sectors/cylinder: 16065
> cylinders: 30400
> sectors/unit: 488392002
[...]
> su-2.05b# disklabel ad5
> # /dev/ad5c:
> bytes/sector: 512
> sectors/track: 63
> tracks/cylinder: 16
> sectors/cylinder: 1008
> cylinders: 484520
> sectors/unit: 488397105
[...]
> So you can see, the "sectors/cylinder", "cylinders", and "sectors/unit"
> are all different, and this results in slightly different final sizes.
> I've set up vinum to create a mirror using the smaller of the two sizes,
> and it seems to be working fine, but I'm still worried about the
> implications of this. Could this mean that one of my hard drives is
> failing? (Again, they're both brand new.) I tried "disklabel -R"'ing each
> drive to look like the other one (booting in single-user mode), but it
> wouldn't let me. So I'm smack out of ideas. I'd appreciate any info or
> suggestions.
Your disks slice tables holding different values for C/H/S geometry. You can
wipe out the slice tables with the dd(1) command and re-initialize them with
fdisk and bsdlabel or sysinstall. There is an example written on this in 'man
8 bsdlabel'.
It seems that your BIOS identifies geometry of both disks listed in your dmesg
output - C/H/S 484521/16/63. This values also shown in your bsdlabel output
of ad5. If you want to re-fdisk and re-bsdlabel ad4 it's necessary that the
disk isn't mounted and that it isn't locked by vinum (see also 'man 4 vinum',
chapters RUNNING VINUM and AUTOMATIC STARTUP).
IMHO there is only one thing that can go wrong with your configuration: If you
are booting your system from the mirror, I would test if both of your drives
are bootable.
- --
Christian Hiris <4711@chello.at> | OpenPGP KeyID 0x3BCA53BE
OpenPGP-Key at hkp://wwwkeys.eu.pgp.net and http://pgp.mit.edu
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.6 (FreeBSD)
iD8DBQFBxNof09WjGjvKU74RAtgWAJ98M9KSoTPsHJU3Ba+JTHrNN2QdmwCfTmwy
bFFRyDuNRfAwc3f1R/6PbeI=
=j26F
-----END PGP SIGNATURE-----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200412190232.15663.4711>