[CentOS] boot with more scsi card -- clarify/more info

Bryan J. Smith thebs413 at earthlink.net
Fri Nov 25 00:17:38 UTC 2005

On Fri, 2005-11-25 at 00:22 +0100, Farkas Levente wrote:
> two more on the mainboard.
> leave 8 on the 3ware (these are the data disks) and replace the mainboard 2.

So you're going to take the 2 IDE disks attached to mainboard ATA
channels and put in SATA or SCSI disks.  Thanx for clarifying what you
meant by SATA or SCSI (I wasn't sure if you mean SATA devices on the
3Ware, or SCSI meaning the 3Ware volumes appear as SCSI).  Sorry I
misread you.

> hangs, there is no opps:-(

If you're putting in a SATA or SCSI that uses a SCSI driver, then your
"hang" is due to the fact that you don't have the booting SATA or SCSI
driver in the initrd.  You'll need to generate a _new_ initrd with the

So now I understand what you meant by ... (from your previous e-mail)

> if i change the order in bios, the kernel still use as
> 3ware scsi0. if i use scsihosts kernel param or load the scsi driver
> (through modprobe.conf) in a reverse order then the kernel hang
> forever during the initialization of the 3ware driver.

So you were talking about the "alias scsi_hostadapter" lines in
your /etc/modules.conf (2.4/CentOS3) or /etc/modprobe.conf
(2.6/CentOS4).  Okay, now I got you.

Remember, the _primary_ reason for the existence of these lines is to
tell "mkinitrd" what order to load the drivers in.  So you'll want
something like ...

  alias scsi_hostadapter (your booting SATA or SCSI card/controller)
  alias scsi_hostadapter1 3w-xxxx

_Unless_ the 3Ware cards are hosting your /boot where your initrd is,
you don't even need the 2nd line.  You _only_ need the first line which
tells initrd to put the proper SCSI driver (and resolve related module
dependencies) in the initrd.

Once you have this correct, you'll need to generate a new initrd:  
  mkinitrd /boot/initrd-`uname -r`-SCSI.img `uname -r`

Then create a new entry in grub.conf that loads this initrd instead of
your old one.  Try booting it and it should load what you need.

Right now your initrd either has nothing, because it was using ATA to
boot, or possibly just the 3Ware driver (which was never used to boot).

-- Bryan

P.S., I would still need to know the _exact_ configuration of your _new_
SATA or SCSI disk to help ensure _all_ files are correct (especially the

1.  What's the _exact_ boot order in the BIOS of the fixed disks

Some newer BIOSes let you re-arrange the exact order of each type of
device (hard drives, optical, floppy, USB, network, etc...) under a
special page.

2.  The card/controller, what driver, etc... of _each_ SATA or SCSI you
are putting in?

3.  What order those devices are showing up as in Linux -- /dev/sda,

Without that _complete_ picture, I can't begin to help you with a
correct /boot/grub/device.map, /boot/grub/grub.conf, etc...

Bryan J. Smith   b.j.smith at ieee.org   http://thebs413.blogspot.com
For everything else *COUGH*commercials*COUGH* there's "ManningCard"

More information about the CentOS mailing list