Arch Linux

Flasher

Member

From: Bavaria / Germany

Registered: 2005-04-24

Posts: 126

Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

Hello!

In the last days I tried to install Archlinux x64 on my server. This server consists of 4 SATA drives. I'm using Linux software Raid with the following configuration:

mdadm --create --verbose /dev/md0 --auto=yes --level=10 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1
mdadm --create --verbose /dev/md1 --auto=yes --level=10 --raid-devices=4 /dev/sda2 /dev/sdb2 /dev/sdc2 /dev/sdd2 
mdadm --create --verbose /dev/md2 --auto=yes --level=0 --raid-devices=4 /dev/sda3 /dev/sdb3 /dev/sdc3 /dev/sdd3

md0 --> / including /boot
md1 --> /data (my storage partiton)
md2 --> my swap partion

In the last step of the installer I don't installed grub and leave the installer without installing a bootloader.

I mounted the /dev folder to /mnt/dev and chrooted in my new system:

chroot /mnt bash

In my new system I installed the new grub2 bootloader with:

pacman -S grub2-bios

In the next step I tried to install the bootloader to the MBR with the following command:

grub_bios-install --boot-directory=/boot --no-floppy --recheck /dev/md0

But I get the following error:

/sbin/grub-probe: error: no such disk.
Auto-detection of a filesystem of /dev/md0 failed.
Please report this together with the output of "/sbin/grub-probe --device-map="/boot/grub/device.map" --target=fs -v /boot/grub" to <bug-grub@gnu.org>

I also tried to install the grub2 directly on my discs with the following command:

grub_bios-install --boot-directory=/boot --no-floppy --recheck /dev/sda

But the error is the same as above.

Following the instruction of the error message I executed the following command:

/sbin/grub-probe --device-map="/boot/grub/device.map

I get a large debug output:

.
/sbin/grub-probe: info: scanning hd3,msdos2 for LVM.
/sbin/grub-probe: info: the size of hd3 is 3907029168.
/sbin/grub-probe: info: no LVM signature found
.
/sbin/grub-probe: info: scanning hd3,msdos1 for LVM.
/sbin/grub-probe: info: the size of hd3 is 3907029168.
/sbin/grub-probe: info: no LVM signature found
.
/sbin/grub-probe: info: scanning hd4 for LVM.
/sbin/grub-probe: info: the size of hd4 is 2068992.
/sbin/grub-probe: info: no LVM signature found
.
/sbin/grub-probe: info: the size of hd4 is 2068992.
/sbin/grub-probe: info: scanning hd4,msdos1 for LVM.
/sbin/grub-probe: info: the size of hd4 is 2068992.
/sbin/grub-probe: info: no LVM signature found
.
/sbin/grub-probe: info: changing current directory to /dev.
/sbin/grub-probe: info: opening md0.
/sbin/grub-probe: error: no such disk.

There is a tutorial for installing grub2 at ArchLinux in the wiki:
https://wiki.archlinux.org/index.php/Grub2

But I can't find any solution for my problem.

Does anybody know a solution for this problem?

Thanks for help

Best regards,

Flasher

Last edited by Flasher (2011-03-03 20:13:13)

hbswn

Member

Registered: 2011-04-04

Posts: 3

Re: Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

I have exactly the same problem on Debian/unstable.
Also same grub version.

Hans

hbswn

Member

Registered: 2011-04-04

Posts: 3

Re: Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

With "-v -v" you get even more debug output.

Maybe it cannot handle the new mdadm format. Here the other partitions have version 0.90. Only the failing md0 has version 1.2:

amd64:~# mdadm -D /dev/md0 | grep Version
        Version : 1.2
amd64:~# mdadm -D /dev/md1 | grep Version
        Version : 0.90

Maybe you should check your version number on the superblock.

hbswn

Member

Registered: 2011-04-04

Posts: 3

Re: Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

With 1.98 it still works fine. I can happily grub-install

grub-probe (GRUB) 1.98+20100804-14

trc

Member

From: Beaver Dam, WI

Registered: 2010-01-14

Posts: 85

Website

Re: Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

Whenever I install grub2 1.99 the old grub-install --no-floppy /dev/partition works for me

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~trc

raku

Member

Registered: 2006-08-23

Posts: 48

Re: Installing grub2 1.99rc1 on Linux Software RAID (/dev/md[0-x])

Maybe it cannot handle the new mdadm format. Here the other partitions have version 0.90. Only the failing md0 has version 1.2:

I'm sure it is the cause of the problem. But not new format. The old one (0.90) is incompatible with grub2.

I hit the same problem and today I managed to fix it.
What I did: I copied /boot to tmp directory, destroyed /dev/md0 (my /boot) with metadata 0.90, created new /dev/md0 (metadata 1.2), copied back /boot content.
After that, grub_bios-install /dev/sda && grub_bios-install /dev/sdb finished without any errors.

---

raku