Is it possble to use /dev/disk/by-id/ in grub.conf?

Is it possble to use /dev/disk/by-id/ in grub.conf?

[Aniruddha]

Hi,

First of all my apologies if this is the wrong medium to post my
question, this was most appropriate medium I could find. 

I wonder  if it is possible (and if so how) to to define a (real_)root
device in grub.conf for a /dev/disk/by-id/. I know it's possible for
uuid but uuid also keeps renaming my harddrives whereas /dev/disk/by-id
works fine. Thanks in advance!

Regards,

Aniruddha

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Pavel Roskin]

On Wed, 2008-07-30 at 20:29 +0200, Aniruddha wrote:
> Hi,
> 
> First of all my apologies if this is the wrong medium to post my
> question, this was most appropriate medium I could find. 
> 
> I wonder  if it is possible (and if so how) to to define a (real_)root
> device in grub.conf for a /dev/disk/by-id/. I know it's possible for
> uuid but uuid also keeps renaming my harddrives whereas /dev/disk/by-id
> works fine. Thanks in advance!

I believe disk IDs are not supported yet.  If you describe your problem
in more details, it may motivate somebody to add disk ID support.  Or
perhaps you are missing a simple solution possible with the current
code.

-- 
Regards,
Pavel Roskin

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Aniruddha]

On Wed, 2008-07-30 at 12:35 -0400, Pavel Roskin wrote:
> I believe disk IDs are not supported yet.  If you describe your problem
> in more details, it may motivate somebody to add disk ID support.  Or
> perhaps you are missing a simple solution possible with the current
> code.

Thanks for your quick response. The problem is that udev keeps changing my harddrive names 
at each boot. Normally my root partition resides on /dev/sdc2. However with each reboot 
this name changes (the last three boots it changed from /dev/sdb2 to /dev/sdf2 to /dev/sdc2). 

I solved this partially by changing the /dev/sdc2 entry in fstab with a /dev/disk/by-id/my_device_id
entry. Unfortunately grub has still /dev/sdc2 configured as root partition. This means I have to guess every
boot which partition-name the root partition resides. I do this by entering devices names (after 
the error message that grub couldn't find my root partition). I start with /dev/sda2 trying each letter 
(sdb2, sdc2, sdd2) until I find the root partition.

In order to solve this problem I would like to set the /dev/disk/by-id/ parameter in my grub.conf.
I hope that explains the problem clearly. Thanks in advance!

Regards,

Aniruddha

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Javier Martín]

2008/7/30 Aniruddha <mailing_list@orange.nl>:
> On Wed, 2008-07-30 at 12:35 -0400, Pavel Roskin wrote:
>> I believe disk IDs are not supported yet.  If you describe your problem
>> in more details, it may motivate somebody to add disk ID support.  Or
>> perhaps you are missing a simple solution possible with the current
>> code.
>
> Thanks for your quick response. The problem is that udev keeps changing my harddrive names
> at each boot. Normally my root partition resides on /dev/sdc2. However with each reboot
> this name changes (the last three boots it changed from /dev/sdb2 to /dev/sdf2 to /dev/sdc2).
>
> I solved this partially by changing the /dev/sdc2 entry in fstab with a /dev/disk/by-id/my_device_id
> entry. Unfortunately grub has still /dev/sdc2 configured as root partition. This means I have to guess every
> boot which partition-name the root partition resides. I do this by entering devices names (after
> the error message that grub couldn't find my root partition). I start with /dev/sda2 trying each letter
> (sdb2, sdc2, sdd2) until I find the root partition.
If your problem is what device name to pass to the kernel command
line, you can use a line like:
    linux /vmlinuz root=UUID=diskuuidhere
and the same with LABEL= if your initrd supports them (like Ubuntu's
default initrd or Gentoo's `genkernel' initrd).
If, on the other hand, your problem is what device to use in GRUB, I
think there is a `search' command you can investigate.

>
> In order to solve this problem I would like to set the /dev/disk/by-id/ parameter in my grub.conf.
> I hope that explains the problem clearly. Thanks in advance!
>
> Regards,
>
> Aniruddha
>
>
>
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Aniruddha]

On Wed, 2008-07-30 at 20:00 +0200, Javier Martín wrote:

> If your problem is what device name to pass to the kernel command
> line, you can use a line like:
>     linux /vmlinuz root=UUID=diskuuidhere
> and the same with LABEL= if your initrd supports them (like Ubuntu's
> default initrd or Gentoo's `genkernel' initrd).
> If, on the other hand, your problem is what device to use in GRUB, I
> think there is a `search' command you can investigate.
> 

If I understand you correctly I have to add the following line to my
grub.conf:

> title=Gentoo Linux (2.6.25-gentoo-r6)
> root (hd0,1)
> kernel /boot/kernel-genkernel-x86-2.6.25-gentoo-r6 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=LABEL=my_label udev
> genkernel --install --bootloader=grub --menuconfig --disklabel all

Furthermore I have to build genkernel with the "--disklabel" option to make it work right?

> genkernel --install --bootloader=grub --menuconfig --disklabel all


Thanks,

Aniruddha

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Javier Martín]

2008/7/30 Aniruddha <mailing_list@orange.nl>:
>
> On Wed, 2008-07-30 at 20:00 +0200, Javier Martín wrote:
>
>> If your problem is what device name to pass to the kernel command
>> line, you can use a line like:
>>     linux /vmlinuz root=UUID=diskuuidhere
>> and the same with LABEL= if your initrd supports them (like Ubuntu's
>> default initrd or Gentoo's `genkernel' initrd).
>> If, on the other hand, your problem is what device to use in GRUB, I
>> think there is a `search' command you can investigate.
>>
>
> If I understand you correctly I have to add the following line to my
> grub.conf:
>
>> title=Gentoo Linux (2.6.25-gentoo-r6)
>> root (hd0,1)
>> kernel /boot/kernel-genkernel-x86-2.6.25-gentoo-r6 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=LABEL=my_label udev

Oh, sorry, I didn't realize you were talking about GRUB Legacy (this
list is mostly about the development of GRUB 2). I think you are
missing some "initrd" (GRUB2) or "module" (GRUB1?) line after the
"linux" (GRUB2) or "kernel" (GRUB1) line - and the genkernel line
should not be in the GRUB config files at all. The exact boot
parameters and configuration should be in the Gentoo documentation: if
I remember my Gentoo times correctly, the Handbook should have all the
info you need. If you mail me a link to the post related to this issue
in the Gentoo forums, I can answer you better than in this list.

>> genkernel --install --bootloader=grub --menuconfig --disklabel all
>
> Furthermore I have to build genkernel with the "--disklabel" option to make it work right?
>
>> genkernel --install --bootloader=grub --menuconfig --disklabel all
>
>
> Thanks,
>
> Aniruddha
>
>
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> http://lists.gnu.org/mailman/listinfo/grub-devel
>

Re: Is it possble to use /dev/disk/by-id/ in grub.conf?

[Aniruddha]

On Wed, 2008-07-30 at 20:25 +0200, Javier Martín wrote:

> Oh, sorry, I didn't realize you were talking about GRUB Legacy (this
> list is mostly about the development of GRUB 2). I think you are
> missing some "initrd" (GRUB2) or "module" (GRUB1?) line after the
> "linux" (GRUB2) or "kernel" (GRUB1) line - and the genkernel line
> should not be in the GRUB config files at all. The exact boot
> parameters and configuration should be in the Gentoo documentation: if
> I remember my Gentoo times correctly, the Handbook should have all the
> info you need. If you mail me a link to the post related to this issue
> in the Gentoo forums, I can answer you better than in this list.
> 

I didn't realize I was running legacy grub :0. I looked in the Gentoo
handbook but I didn't find anything useful:
http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1&chap=10#doc_chap2

Here's the thread in the Gentoo forums with my current problem:
http://forums.gentoo.org/viewtopic-p-5167749.html#5167749

And here's a thread with some additional information:
http://forums.gentoo.org/viewtopic-t-701101-highlight-.html

Any help would be appreciated!

Regards,

Aniruddha

P.S.
Now I go and try to boot this kernel:

> title=Gentoo Linux (2.6.24-gentoo-r8)
> root (hd0,1)
> kernel /boot/kernel-genkernel-x86-2.6.24-gentoo-r8 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=LABEL=/dev/disk/by-id/scsi-SATA_SAMSUNG_HD103UJS13PJ1MQ318013-part2 udev
> initrd /boot/initramfs-genkernel-x86-2.6.24-gentoo-r8