| View previous topic :: View next topic |
| Author |
Message |
hanj
Veteran
Joined: 19 Aug 2003
Posts: 1490
|
 Posted: Thu Mar 29, 2007 5:31 am Post subject: Possible MBR Grub corruption -- need help |
 |
|
Not sure if this is the right board to post this. On one of my boxes, I'm experiencing possible MBR corruption. October of last year, we rebooted the box and it came up with grub prompt with cursor. The only way to get it up was to boot into liveCD, mount partitions and run grub set up again. I thought that was weird and checked the disk and everything checked out. That box has been up since then and I was trying to load a new kernel on it today.. and again on reboot, it got stuck on grub prompt. I walked the tech through the liveCD/grub set up, and I was back in business.
I'll be on site tomorrow, so I'll be able to try some manual reboots with myself present, but wanted to ask if anyone has seen this behaviour before. Also, is there anything I can check to see if there are problems. Would this indicate a bad disk? Any work arounds for this? Setup grub in another partition other than boot?
Any suggestions are greatly appreciated.
Thanks!
hanji
_________________
Server Admin Blog - Uno-Code.com |
|
| Back to top |
|
 |
PMcCauley
Apprentice
Joined: 14 Mar 2006
Posts: 283
Location: Alberta, Canada
|
| Posted: Thu Mar 29, 2007 5:59 am Post subject: |
|
|
| hanj wrote: | Not sure if this is the right board to post this. On one of my boxes, I'm experiencing possible MBR corruption. October of last year, we rebooted the box and it came up with grub prompt with cursor. The only way to get it up was to boot into liveCD, mount partitions and run grub set up again. I thought that was weird and checked the disk and everything checked out. That box has been up since then and I was trying to load a new kernel on it today.. and again on reboot, it got stuck on grub prompt. I walked the tech through the liveCD/grub set up, and I was back in business.
I'll be on site tomorrow, so I'll be able to try some manual reboots with myself present, but wanted to ask if anyone has seen this behaviour before. Also, is there anything I can check to see if there are problems. Would this indicate a bad disk? Any work arounds for this? Setup grub in another partition other than boot?
Any suggestions are greatly appreciated.
Thanks!
hanji |
While I could only speculate as to the cause if you get a grub prompt then you more than likely can boot the system from that. Try this: (you need to modify to match the proper boot options if using other kernel args etc.)
| Code: | root (hdx,x)
kernel /kernel_location root=/dev/xxx
boot
|
You can also run setup (hdx) after root and that may effectivly reinstall grub. And one other thing is configfile /grub/grub.conf may display your boot menu. This isn't something that should just happen on it's own. If there is more than one HDD maybe grub is installed on the other but not configured and the system is booting that or maybe one of the critical files were affected. Make sure your /etc/fstab specifies the boot partition not to be auto mounted and this may prevent reoccurance as well. Oh and to answer your question yes I have ran into this before but know of no specific cause and seems unusual that you are seeing it twice in such a short time. As an extra precaution you can run hardware diagnostics(badblocks, memtest86, etc). Check log files for anything odd as well.
Patrick |
|
| Back to top |
|
|
deface
Apprentice
Joined: 17 Mar 2007
Posts: 205
|
|
| Back to top |
|
|
hanj
Veteran
Joined: 19 Aug 2003
Posts: 1490
|
| Posted: Thu Mar 29, 2007 1:19 pm Post subject: |
|
|
| deface wrote: | | Are you sure your not automounting the /boot partition? Is it on its own partition? |
How can I verify that it's autmounting? And yes, it's on it's own partition.
hanji
_________________
Server Admin Blog - Uno-Code.com |
|
| Back to top |
|
|
hanj
Veteran
Joined: 19 Aug 2003
Posts: 1490
|
| Posted: Thu Mar 29, 2007 1:23 pm Post subject: |
|
|
| PMcCauley wrote: |
While I could only speculate as to the cause if you get a grub prompt then you more than likely can boot the system from that. Try this: (you need to modify to match the proper boot options if using other kernel args etc.)
| Code: | root (hdx,x)
kernel /kernel_location root=/dev/xxx
boot
|
You can also run setup (hdx) after root and that may effectivly reinstall grub. And one other thing is configfile /grub/grub.conf may display your boot menu. This isn't something that should just happen on it's own. If there is more than one HDD maybe grub is installed on the other but not configured and the system is booting that or maybe one of the critical files were affected. Make sure your /etc/fstab specifies the boot partition not to be auto mounted and this may prevent reoccurance as well. Oh and to answer your question yes I have ran into this before but know of no specific cause and seems unusual that you are seeing it twice in such a short time. As an extra precaution you can run hardware diagnostics(badblocks, memtest86, etc). Check log files for anything odd as well.
Patrick |
If I remember correctly, the first time this happened I tried this and it couldn't see my device from grub prompt. I'll try it again today if it happens to verify this.
There is only one harddrive, and grub is set to run in hd0,0
This is what I have in /etc/fstab for /boot
| Code: | | /dev/hda1 /boot reiserfs noauto,noatime 1 2 |
We'll run some diagnostics tonight on the drive, but I have not seen any messages indicating write errors, etc via messages. I keep a close eye on the logs, and I would definitely see those messages.
Thanks much for both of your replies.
hanji
_________________
Server Admin Blog - Uno-Code.com |
|
| Back to top |
|
|
jburns
Veteran
Joined: 18 Jan 2007
Posts: 1214
Location: Massachusetts USA
|
| Posted: Thu Mar 29, 2007 6:37 pm Post subject: |
|
|
Changing the fstab entry for /boot to | Code: | | /dev/hda1 /boot reiserfs noauto,noatime,notail 1 2 |
and run grub set up again may help. |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
Installing Gentoo
