[SOLVED] Problem installing CentOS with a RAID 1

Lisandro1987 · Post by **Lisandro1987** » 2012/04/25 17:39:59

I try install CentOS 6.2 with a RAID 1 following the steps in http://wiki.centos.org/HowTos/SoftwareRAIDonCentOS5, with the only exception that in 'method 1 of GRUB' I have to use 'root (hd1,1) instead of 'root (hd1,0)'.

The system boot perfect with two disks, but when I disconnect one (emulating a failure) the next error appear:

kernel panic - not syncing: attempted to kill init!
panic occurred, switching back to the console

What can I do?

PD: Sorry for my bad english :-(

Post by **TrevorH** » 2012/04/25 20:10:05

There was a bug in the original dracut version that shipped with CentOS 6.2 that caused boots from a broken RAID 1 array to fail. Have you yum updated your system? If you have then you have the latest version of dracut and need to rebuild the initramfs with it using something like

[code]
dracut /boot/initramfs-2.6.32-220.el6.img 2.6.32-220.el6
[/code]

Lisandro1987 · Post by **Lisandro1987** » 2012/04/26 15:48:28

Thanks a lot! I'll try with that...

Lisandro1987 · Post by **Lisandro1987** » 2012/05/09 19:24:47

In '/boot' I have:

[quote][b][root@ls2 administrator]# dracut /boot/[/b]
config-2.6.32-220.13.1.el6.x86_64
config-2.6.32-220.el6.x86_64
efi/
grub/
initramfs-2.6.32-220.13.1.el6.x86_64.img
initramfs-2.6.32-220.el6.x86_64.img
initrd-2.6.32-220.13.1.el6.x86_64kdump.img
initrd-2.6.32-220.el6.x86_64kdump.img
lost+found/
symvers-2.6.32-220.13.1.el6.x86_64.gz
symvers-2.6.32-220.el6.x86_64.gz
System.map-2.6.32-220.13.1.el6.x86_64
System.map-2.6.32-220.el6.x86_64
vmlinuz-2.6.32-220.13.1.el6.x86_64
.vmlinuz-2.6.32-220.13.1.el6.x86_64.hmac
vmlinuz-2.6.32-220.el6.x86_64
.vmlinuz-2.6.32-220.el6.x86_64.hmac[/quote]

I execute the next command:

[quote][b][root@ls2 administrator]# dracut /boot/initramfs-2.6.32-220.el6.x86_64.img --force[/b]
E: Will not override existing initramfs (/boot/initramfs-2.6.32-220.el6.x86_64.img) without --force[/quote]

What's wrong? Thanks you again! ;)

pschaff · Post by **pschaff** » 2012/05/09 19:45:03

You did not give all the required parameters, you did not specify a different filename for the initramfs, and you did not use the latest kernel. Try[code]
cd /boot
dracut initramfs-2.6.32-220.13.1.el6.x86_64_new.img 2.6.32-220.13.1.el6.x86_64
mv initramfs-2.6.32-220.13.1.el6.x86_64.img initramfs-2.6.32-220.13.1.el6.x86_64_old.img
mv initramfs-2.6.32-220.13.1.el6.x86_64_new.img initramfs-2.6.32-220.13.1.el6.x86_64.img[/code]
Welcome to the CentOS fora. Please see the recommended reading for new users linked in my signature.

Lisandro1987 · Post by **Lisandro1987** » 2012/05/10 14:50:56

Thanks so much!

I just try that commands in the terminal from CentOS, and when I disconnect a disk (like a disk failure) the system boots, but when I disconnect the other disk the system doesn't boot (black display with a pointer flashing).

Do I forget anything?

jlehtone · Post by **jlehtone** » 2012/05/10 14:57:44

Each disk has its own MBR; they are not mirrored.
Filesystem on software RAID-1 can be accessed directly without the md subsystem. Read-only access is safe.

Grub stage1 within MBR has a pointer to a partition that contains the /boot. Either one of the disks lacks stage1 from its MBR, or the pointer refers to the other disk. When the other disk is "dead", the pointer is wrong.

Lisandro1987 · Post by **Lisandro1987** » 2012/05/10 15:42:41

Thanks jlehtone! And... How can I resolve that?

When I install CentOS y formated the partitions in 'ext4' and in http://wiki.centos.org/HowTos/SoftwareRAIDonCentOS5 says 'ext3'... Is that a problem?

pschaff · Post by **pschaff** » 2012/05/10 17:21:11

No. For CentOS-5 ext3 was the default. For CentOS-6 it is ext4.

Lisandro1987 · Post by **Lisandro1987** » 2012/05/10 17:22:59

Thanks pschaff! :) Any idea about the other question?

CentOS