[Bootcd-user] generic system rescue diskk

[Erik Rossen]

On Wed, Sep 12, 2007 at 09:45:26PM -0500, John Heim wrote:
> Anyway,  I was wondering if bootcdwrite is a good tool for creating generic 
> system rescue CDs.

It might be an OK starting point for a given machine, but the modules
that are activated from the initrd are usually just those of the machine
where you ran bootcdwrite.  If you try to use the CD on another machine
with different hardware (e.g. drive controlers), there is no guarantee
that the CD will work.

> It mostly works. One thing is that it doesn't work on machines with sata 
> hard drives. Correct me if I'm wrong but I think the CD drive would be hda 
> in machines with sata drives.

No, I have seen machines with SATA CD drives were the device is detected
as SCSI, i.e. /dev/scdN.

> I am aware that you can specify hda or hdc at the boot prompt but if
> you're blind, that's difficult. The screen reader doesn't start until
> after the kernel loads.  There must be some way to have it detect the
> CDROM drive because grml and the other live distros don't make you
> specify the CDROM drive.

The problem is the necessity to specify the "root=" option on the kernel
command line.  If you are using /dev/hd?N or /dev/sd?N or /dev/scdN
method, you are stuck.  You have to know in advance which one to use and
be able to select it.

But there may be another way of specifying the "root" kernel option by
referring to the /dev/disk/{by-uuid,by-path,by-id} hierarchy for
specifying disks.  If, for example, the CDROM has a fixed UUID (call it
"blah"), perhaps specifying "root=/dev/disk/by-uuid/blah" would work in
all cases and one would no longer need to make a choice from a boot
menu.

-- 
Erik Rossen           A. It breaks the flow of conversation.
rossen at prolibre.com   Q. Why is top-quoting annoying? 
http://www.prolibre.com                OpenPGP key: 0816CC1B