Mailinglist Archive: opensuse (3637 mails)

[Philipp Thomas <pthomas@xxxxxxx>]

* Paul Abrahams [Sat, 05 May 2001 22:28:50 -0400]:

>I'm using a Tyan S2390 motherboard.   Do I need to rejigger the kernel before
>I take my computer apart to install the ATA controller?

Is there any reason why you want to move the drive to the offboard
controller? It does depend on the hard disk, but only very few exceed
UDMA33 speed and *none* exceed UDMA66. So if your onboard controller
supports UDMA33, chances are very high that you will see no noticeable
speedup by moving the disk.

Even if a disk supports UDMA100, that does not mean that it actually can
make use of the higher transfer speed. 

UDMA100 currently is nothing more then a marketing vehicle as there is
*no* disk that even comes near UDMA66 speed.

If this is the only disk you have or if you move all disks to the
offboard controller, there is no need to reconfigure the kernel. Change
/etc/fstab so that hda becomes hde and add this to your /etc/lilo.conf
in the global section:

disk=/dev/hde
bios=0x80

To tell lilo that after booting hde is the first disk in the system.
This is because Linux consistently names disks in the order they're
attached:

    master on 1st channel:  hda
    slave       "        :  hdb

    master on 2nd channel:  hdc
    slave   "  "    "    :  hdd

and so on, no matter if there are disks attached to a channel or not.
The BIOS in contrast scans for available disks and numbers them in the
order it finds them, beginning with 0x80h. Lilo by default thinks that
hda will be the first disk, i.e. will be accessible as BIOS drive 0x80h.


And of course rerun lilo after changing lilo.conf.

-- 
Penguins to save the dinosaurs
                     -- Handelsblatt on Linux for S/390