I have a machine that's been configured as follows using its BIOS tools:
SATA-0 is a 160 GiB drive used as boot
SATA-1 and SATA-2 are both 500 GiB drives and were configured as a
RAID-1 in BIOS.
When the system boots up, BIOS reports 1 160 GiB SATA drive, and 1
Logical volume as RAID-1 ID#0 500 GiB, which is what I would expect it
to report, as the two drives are now raided together.
However, when I boot into the Centos installer and I get to
configuring the partitions, it lists both sda, sdb, and sdc as
available. Both sdb and sdc are 500 GiB. I would've expected to only
see one drive for the RAID setup.
Can someone explain why I see both drives and how am I supposed to
configure them? I thought if I configured the BIOS to raid them, I
wouldn't have to do anything in the OS other than to format the thing
and expect it to work.
--
W | It's not a bug - it's an undocumented feature.
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Ashley M. Kirchner <mailto:ashley at pcraft.com> . 303.442.6410 x130
IT Director / SysAdmin / Websmith . 800.441.3873 x130
Photo Craft Imaging . 3550 Arapahoe Ave. #6
http://www.pcraft.com ..... . . . Boulder, CO 80303, U.S.A.
On Wed, Apr 11, 2007 at 11:32:22AM -0600, Ashley M. Kirchner enlightened us:> I have a machine that's been configured as follows using its BIOS tools: > > SATA-0 is a 160 GiB drive used as boot > SATA-1 and SATA-2 are both 500 GiB drives and were configured as a > RAID-1 in BIOS. > > When the system boots up, BIOS reports 1 160 GiB SATA drive, and 1 > Logical volume as RAID-1 ID#0 500 GiB, which is what I would expect it > to report, as the two drives are now raided together. > > However, when I boot into the Centos installer and I get to > configuring the partitions, it lists both sda, sdb, and sdc as > available. Both sdb and sdc are 500 GiB. I would've expected to only > see one drive for the RAID setup. > > Can someone explain why I see both drives and how am I supposed to > configure them? I thought if I configured the BIOS to raid them, I > wouldn't have to do anything in the OS other than to format the thing > and expect it to work.You would be able to do that if you were using a real RAID card, but the crap that comes on your motherboard is nothing more than a fancy hardware interface to software drivers that do the RAID. See http://en.wikipedia.org/wiki/FakeRAID for more details. Your best bet is to either get a real hardware RAID card (3ware, etc.) or to use the software RAID built into linux (md). Matt -- Matt Hyclak Department of Mathematics Department of Social Work Ohio University (740) 593-1263
On Wed, 11 Apr 2007 at 11:32am, Ashley M. Kirchner wrote> > I have a machine that's been configured as follows using its BIOS tools: > > SATA-0 is a 160 GiB drive used as boot > SATA-1 and SATA-2 are both 500 GiB drives and were configured as a RAID-1 > in BIOS. > > When the system boots up, BIOS reports 1 160 GiB SATA drive, and 1 Logical > volume as RAID-1 ID#0 500 GiB, which is what I would expect it to report, as > the two drives are now raided together. > > However, when I boot into the Centos installer and I get to configuring > the partitions, it lists both sda, sdb, and sdc as available. Both sdb and > sdc are 500 GiB. I would've expected to only see one drive for the RAID > setup. > > Can someone explain why I see both drives and how am I supposed to > configure them? I thought if I configured the BIOS to raid them, I wouldn't > have to do anything in the OS other than to format the thing and expect it to > work.FAQ. http://linux-ata.org/faq-sata-raid.html -- Joshua Baker-LePain Department of Biomedical Engineering Duke University