Arch Linux

DnF

Member

Registered: 2010-08-15

Posts: 19

[raid][solved] Grub reinstall problem, system hangs during boot

Hi guys,

I had a problem with grub, I incidentally ran install-grub in console as root - please don't ask how it is possible - and of course my system failed to reboot.
I have single install of arch on software raid from 3 harddisks. boot, swap as raid1 and root, home as raid5.

I have tried some advices from arch wiki (installing arch on raid) and from other grub wiki pages, and now I can see system selection again, but after selecting Arch linux, boot ends after assembling raid drives. 

this is the end of the output I got, I can't scroll up, the keyboard is inactive. but t says the same for all four raid disks -

md: md3 stopped.
md: bind<sdb3>
md: bind<sdc3>
md: bind<sda3>
md/raid:md3: device sda3 operational as raid disk 0
md/raid:md3: device sdc3 operational as raid disk 2
md/raid:md3: device sdb3 operational as raid disk 1
md/raid:md3: allocated 3222kB
md/raid:md3: raid level 5 active with 3 out of 3 devices, algorithm 2
md3: detected capacity change from 0 to 5999275840
mdadm: /dev/md3 has been started with 3 drives
Waiting 10 second for device /dev/md1 ...
md3: detected capacity change from 0 to 5999275840
 md3: unknown partition table
ERROR:  Root device mounted successfully, but /sbin/init does not exist.
Bailing out, you are on your own. Good luck.

/bin/sh: can't access tty; job control turned off
[ramfs /]#

Unfortunately I can't say what is before this output, I cannot scroll up.

I have several ideas and questions, but I don't want to continue and break it more than it is now:

* I had md0 to md4 raid devices  - but there are only md1 - 3, on third it stops - it is root, but I think it used to be md2...
* I have installed grub on sda(bc)1 as from the wiki - but without the raid assembled - I don't understand well this part
* Maybe I can reinstall, but what I will loose - system settings? Or can I reinstall and leave system as was, only repair grub and disk layout?
* What is the "unknown partition" line? may it be a problem?

Thanks for your answers, I'm a newbie and I have to solve such a situation for the first time.

Last edited by DnF (2010-09-23 06:40:05)

DnF

Member

Registered: 2010-08-15

Posts: 19

Re: [raid][solved] Grub reinstall problem, system hangs during boot

additional info discovered while trying to figure it out:

When I manually assemble all my disks to the state before the accident (from arch installation cd), I can see boot/grub directory on /md0 (/boot)
In the menu.lst there is lot of garbage but no usual list. Only on the last line I can read

 ^@Geom^@Read^@ Error^@ ***garbage again***

I could try to repair it, but what about the raid numbering md1-md3 instead of md0-md3 ?

DnF

Member

Registered: 2010-08-15

Posts: 19

Re: [raid][solved] Grub reinstall problem, system hangs during boot

Well, I have found that now my /root is on /dev/md3 - don't ask why - and on one of the forums I have also found one guy who had same problem with changed device names, too - so I have repaired menu.lst from last post, and now it boots, with error something like "/boot cannot be mounted" but system seems to work fine. I will investigate this last error tomorrow...

Last edited by DnF (2010-09-20 22:22:30)