Problem at Boot...How to configure grub?

frankifol · 2010-03-07 08:53:02

I installed the last Arch, core version.

I have two hdd. An internal Sata (with windows 7 on it) and an external sSata with arch.

fdisk -l give this output:

sda1, sda2, sda3 : partitions with NTFS, from win7

sdb1 boot
sdb2 swap
sdb3 root
sdb4 home

I don't need to configure grub to boot win7 because I set the bios to start the boot procedure from the eSata. So, when I need arch all I need to do is switch on the external HDD. If I need win7, I left the eSata box switched off.

How should I configure grub?

Now it is:

root (hd1,0)
kernel /vmlinuz26 root=/dev/sdb3 ro
initrd /kernel26.img

but it doesn't boot. I think root (hd1,0) is ok (the second hdd, the first partition). The directory with kernel I don't know. But I tried with sdb1,sdb2, sdb3 without any advantage.

Any idea?

madeye · 2010-03-07 09:06:54

You should make sure the drive order does not change. That sometimes happens.
Your external drive may very well be recognized as sda when you reboot your machine!

What grub error do you get?

frankifol · 2010-03-07 09:27:49

filesistem type unknown, partition type 0x7
error 17: cannot mount selected partition

I tried to change root in (hd0,0) and I had a kernel Panic. The curious thing is that in a first attempt of installation on the Esata I unplugged the internal hdd and I had no problem.

PS: with both suse and mint last versions, everything worked well out of the box
PPS: launcing slax with both the hdd plugged on, fdisk -l gave me always sda for the internal hdd and sdb for external hdd

madeye · 2010-03-07 09:46:12

error 17 indicates that you have a messed up partition tabel.
http://wiki.archlinux.org/index.php/Grub#GRUB_Error_17 has some details on that.

Another thing I normally do is use the UUID of the root partition instead of the device name?

root=/dev/disk/by-uuid/<uuid-string>

frankifol · 2010-03-07 09:52:47

the default installation showed a string with UID and it didn't worked.

madeye · 2010-03-07 10:18:35

Until you get rid of "error 17", it will not matter whether you use the device or the uuid in the kernel line.
The problem is that grub can't find its stage1 file. This is normally because a wrong device is used in the

root (hdx,x)

Try to locate the stage1 file from within a grub prompt. (e.g. boot on a livecd and issue grub in a terminal)

frankifol · 2010-03-07 10:32:12

I unplugged the internal sata. I defined The right root for grub hd(0,0) and the string for kernel with uuid. Now the system starts, but i have this new message:

fileystem check failed
Repair manually an reboot. Note that the root file system is currently mounted read-only. To remount it read-write tipe: mount -n -o remount, rw /
When you exit the maintenance shell the system will reboot automatically.
Give root password for maintenance (or type Control-D to continue)

madeye · 2010-03-07 10:43:52

When you installed arch, did you have the internal drive unplugged? Perhaps you need to change the devices used in the /etc/fstab file. Now that you only have one drive attached, it will have the device sda!

In fstab you can also use UUID instead of regular devices.
Either just use the path

/dev/disk/by-uuid/<uuid string>

or you can use

UUID=<uuid string>

EDIT:
I am not sure what is happening here, but I have a similar setup with my laptop used at work. I have an external drive with linux on it.
When I installed linux, the drive was called sdb. That didn't change when I booted a livecd, but when I booted of the external drive it became sda. This happens due to changing the boot order in the bios.

Last edited by madeye (2010-03-07 10:47:21)

Arch Linux

#1 2010-03-07 08:53:02

Problem at Boot...How to configure grub?

#2 2010-03-07 09:06:54

Re: Problem at Boot...How to configure grub?

#3 2010-03-07 09:27:49

Re: Problem at Boot...How to configure grub?

#4 2010-03-07 09:46:12

Re: Problem at Boot...How to configure grub?

#5 2010-03-07 09:52:47

Re: Problem at Boot...How to configure grub?

#6 2010-03-07 10:18:35

Re: Problem at Boot...How to configure grub?

#7 2010-03-07 10:32:12

Re: Problem at Boot...How to configure grub?

#8 2010-03-07 10:43:52

Re: Problem at Boot...How to configure grub?

Board footer