[gentoo-user] [OT] ESATA drive changes the root device -- how to deal with it?

2009-06-11 Thread walt

Okay, my root partition is on /dev/sda (normally), which is a sata
drive connected to the onboard sata controller.

The problem is that I also have a plug-in ESATA docking station, which
is not always powered on.  When it *is* powered on, my kernel names the
disk /dev/sda, and that forces the root device to be named /dev/sdb
instead of sda.  Crashing ensues during bootup.

The machine's BIOS doesn't even recognize the ESATA controller, so
I can't fiddle with anything there.

Anyone have any ideas how to get a kernel to mount the root partition
based on the pci slot number or something equivalent?

I've tried using a disk label in fstab instead of a device name, but the
problem is that the kernel mounts the wrong partition before it has a
chance to read fstab.

I've also tried using rdev to set the root device to the disk's major
and minor numbers but that fails because the kernel switches the minor
device numbers along with the device names.

Any clues would be much appreciated.





Re: [gentoo-user] [OT] ESATA drive changes the root device -- how to deal with it?

2009-06-11 Thread Volker Armin Hemmann
On Donnerstag 11 Juni 2009, walt wrote:
 Okay, my root partition is on /dev/sda (normally), which is a sata
 drive connected to the onboard sata controller.

 The problem is that I also have a plug-in ESATA docking station, which
 is not always powered on.  When it *is* powered on, my kernel names the
 disk /dev/sda, and that forces the root device to be named /dev/sdb
 instead of sda.  Crashing ensues during bootup.

 The machine's BIOS doesn't even recognize the ESATA controller, so
 I can't fiddle with anything there.

 Anyone have any ideas how to get a kernel to mount the root partition
 based on the pci slot number or something equivalent?

 I've tried using a disk label in fstab instead of a device name, but the
 problem is that the kernel mounts the wrong partition before it has a
 chance to read fstab.

 I've also tried using rdev to set the root device to the disk's major
 and minor numbers but that fails because the kernel switches the minor
 device numbers along with the device names.

 Any clues would be much appreciated.

afaik you can use labels in grub too.



Re: [gentoo-user] [OT] ESATA drive changes the root device -- how to deal with it?

2009-06-11 Thread Dirk Heinrichs
Am Donnerstag 11 Juni 2009 17:32:18 schrieb walt:
 I've tried using a disk label in fstab instead of a device name, but the
 problem is that the kernel mounts the wrong partition before it has a
 chance to read fstab.

fstab is the wrong place. It should be on the kernel command line (that thing 
you configure in your bootloader's config).

HTH...

Dirk


signature.asc
Description: This is a digitally signed message part.


Re: [gentoo-user] [OT] ESATA drive changes the root device -- how to deal with it?

2009-06-11 Thread Stroller


On 11 Jun 2009, at 16:37, Volker Armin Hemmann wrote:

On Donnerstag 11 Juni 2009, walt wrote:

...
The problem is that I also have a plug-in ESATA docking station,  
which
is not always powered on.  When it *is* powered on, my kernel names  
the

disk /dev/sda, and that forces the root device to be named /dev/sdb
instead of sda.  Crashing ensues during bootup.
...
I've tried using a disk label in fstab instead of a device name,  
but the

problem is that the kernel mounts the wrong partition before it has a
chance to read fstab.
...

afaik you can use labels in grubtoo.


I believe  you need an initrd/initramfs in order to do so.

See Neil Bothwick's first post:
http://www.mail-archive.com/gentoo-user@lists.gentoo.org/msg81584.html

Stroller.