*** Announcement: dmraid 1.0.0.rc6 *** Call for testers

[Molle Bestefich]

hirac.kasapoglu at turkcell.com.tr wrote:
> Hello, I would like to be a tester.
> But I need help to install linux in my system.

> My system is:
> - Shuttle SB81PIntel 915G chipset
>   (with Intel Soft RAID – Intel Matrix Storage called by Intel)
> - Intel P4 2.8 Ghz LGA775512 MB RAM
> - 2 x 160 GB Seagate SATA disk
>  (Configured as single RAID 0 disk)

> I created following partitions on my RAID 0:
> Primary Partition 1: 10 GB NTFS: Windows XP Installed [...]
> Primary Partition 2: 290 GB Extended Partition
> Logical Partition 1: 10 GB ext2 fs
> Logical Partition 2: 1 GB swap partition
> Logical Partition 3: 279 GB NTFS: Windows D drive

> I created linux ext2 and swap partitions with Partition Magic.
> Interestingly when I start windows 98SE installation CD without any RAID
> driver, I can see RAID drive partitions, and I can partition the disk with
> Partition Magic.

That is because the RAID BIOS simulates a single disk.
It does this by hooking a software interrupt known as INT13.
Boot loaders, DOS, Windows and a bunch of other stuff uses this interrupt
to access the disk.  Therefore, they only see 1 disk, although it is really
a RAID array.

The INT13 calls are "stacked".  This means that the software that your
RAID BIOS hooks into INT13 checks to see if a request made is to one of
the disks it is simulating.  In case it is to a different (non-RAID or on
a different controller) disk, it just calls the old handler, which is
"lower in the stack".

So much for that.

Under Linux, only the boot loader generally uses INT13.
The boot loader just loads the kernel.
In order for disk accesses to be fast and more sophisticated, the kernel
has it's own disk access mechanism, which resides in something you could
call a IDE hardware driver module or whatever you fancy.

I think Windows might have a fallback mechanism, so that it uses INT13 in
case it can't find a driver, but really, I'm not sure.  Perhaps only
in Safe Mode.

> But I cannot install Windows XP and Linux without RAID drivers.

Ok.

> When I try to install FC3, it cannot find any hard drive, and aborts the
> installation. So how can I install FC3 to my Logical Partition 2?

In the installer, you can break out into a shell by pressing CTRL-ALT-F2.
Once in the shell, type "dd if=/dev/hda of=test count=1".
If the hardware driver needed to access your disks is correctly in place,
this should succeed.  The driver might not be loaded until right before
the 'disk partition' step is reached in the installer, so perhaps you
need to click 'next' a couple of times before opening the shell.

Once you've established that the hardware driver is in place, you need to
have a piece of software that reads RAID metadata from the two physical
disks and simulates one disk on top of the hardware driver.
This software is dmraid.

I've got no idea if dmraid is included with Fedora Core 3, but it's RedHat,
so perhaps.

Otherwise, download the DMRAID LiveCD generously provided by Gerte Hoogewerf.
You should be able to download it here:
http://tienstra4.flatnet.tudelft.nl/~gerte/gen2dmraid/

Unfortunately, it won't install anything.
And you can't test RAID1.
RAID1 in dmraid is broken anyway, at least for HighPoint controllers.