[CentOS] Re: Intel RAID controller -- Is it the FRAID volume? Or just the disk?

Bryan J. Smith b.j.smith at ieee.org
Thu Sep 8 21:42:58 UTC 2005


Mark Belanger <mark_belanger at ltx.com> wrote:
> I dont' know - how do I tell?
> I fired up a 3.5 install, it saw the disks, and I
> installed.

What disks did it see?

FRAID is just that, fake RAID.  The OS sees the actual disks.
 You have to use a 100% software hack to trick the OS into
organizing the disks differently.

What I've commonly seen is someone install Linux on a FRAID
controller and install to the disks directly, _no_
understanding whatsoever of the FRAID organization.

So at next boot, you either can't boot, or the FRAID 16-bit
Int13h disk services realizes that the FRAID organizaton has
been _destroyed_ and just boots the "raw" disk.  If you were
dual-booting and had previously installed Windows, it's now
_toasted_.

Again, support of the "FRAID organization" is required
_in_addition_ to the "ATA/SATA" channels.  The ICH5/6/7 ATA
channel might be supported, but the kernel utterly ignores
the FRAID organization.

You have to be very careful.

> Creating a 100Meg files seems pretty good:
> time dd if=/dev/zero of=/var/tmp/blah bs=1024 count=100000
> 100000+0 records in
> 100000+0 records out

But what devices?
Give me an output of "dmesg" and "df".

Now based on those devices, give me an output of "fdisk -l"
on each.

We could also look at the /proc filesystem after that.


-- 
Bryan J. Smith                | Sent from Yahoo Mail
mailto:b.j.smith at ieee.org     |  (please excuse any
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