[CentOS] booting from copied ext3 software raid fs to normal fs

dan1 dan1 at edenpics.com
Sat Sep 24 12:20:56 UTC 2005


Hello.

I am trying to boot CentOS 4 from a copy of an ext3 software RAID 1 
filesystem (md) which has been copied to a normal ext3 filesystem (hd). I am 
almost getting there, exept that the system hangs after booting the kernel.
I copied the datas from the /boot and / partitions to two similar partitions 
on the backuped disk with mirrordir (can also be done with cp or dd). I have 
setup the new disk with grub and I can reach the grub stage 2. It will also 
boot the kernel properly, but it will hang during the SElinux initialisation 
(which is disabled). I don't know exactly if it's a mount or SElinux 
problem.
Also, it seems that the raid device is trying to be initialised, and I don't 
have an md but an hd on that drive. This comes probably from the original 
setup.

My question is: does somebody know how I can change that behaviour and let 
linux mount the hd instead of the md coming from the original ?
Do I need to boot another vmlinuz image or another initrd for it to work 
properly ? In this case, how could I generate those new images ?

The output of the boot sequence is the following:

Mounting sysfs
Creating /dev
Starting udev
Loading raid1.ko module
md: raid1 personnality registered as nr 3
Loading jbd.ko module
Loading ext3.ko module
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
Creating root device
Mounting root filesystem
kjournald starting. Commit interval 5 seconds
EXT3-fs: mounted filesystem with ordered data mode.
mount: error 2 mounting none
Switching to new root
SElinux: Disabled at runtime
SElinux: Unregistering netfilter hooks

Then, it hangs here undefinitely.


Here is my menu.lst grub file on the backup disk I want to boot from:
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.9-11.106.unsupported)
        root (hd0,0)
        kernel /vmlinuz-2.6.9-11.106.unsupported root=/dev/hda3
        initrd /initrd-2.6.9-11.106.unsupported.img

Here is it's fstab:
none                    /dev/pts                devpts  gid=5,mode=620  0 0
none                    /dev/shm                tmpfs   defaults        0 0
none                    /proc                   proc    defaults        0 0
none                    /sys                    sysfs   defaults        0 0
/dev/hda1               /boot                   ext3    defaults        0 0
/dev/hda2               swap                    swap    defaults        0 0
/dev/hda3               /                       ext3    defaults        0 0
/dev/fd0                /media/floppy           auto 
pamconsole,exec,noauto,managed 0 0



Any help is greatly appreciated.

Thanks,
Daniel






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