Cannot boot after power failure while in sleep mode

lesha_n · n00b Joined: 15 Nov 2007 Posts: 65

Dear Gentoo experts,

I cannot boot after a power failure at my home during which my system was in the sleep mode. When I boot (kernel 2.6.39) in the usual way I very quickly get the following prompt:

Logicien · Posted: Wed May 09, 2012 5:42 am Post subject:

Hi,
a power failure mean that the mounted filesystems of your Gentoo have been quit in an unclean state. If you boot on a read only root filesystem, that's mean you need to check it first an others unclean one to. So, boot on a Linux media that allow you to make a fsck on those to make them clean. Than, your subsequent Gentoo boot can be normal.
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Paul

lesha_n · n00b Joined: 15 Nov 2007 Posts: 65

Logicien,

Thank you for your help. Following your advice I booted with Gentoo LiveDVD 12.1 and ran fsck on the root (/) filesystem, as well as on /usr, /home, /tmp, /var and /opt (note that all of these filesystems except / are under LVM, but their volume group and logical volumes were correctly found & activated with vgscan and vgchange -a y).

fsck was clean on all except /var where a few problems were fixed.

I am able to mount all of these and list their contents, at first glance looks fine.

When trying a normal boot after that I still get the exact same error as before. Not sure how to debug this further. dmesg does not seem to indicate anything that I recognize as relevant. Are there other logs I can check to pinpoint the exact problem that happens on boot?

Thanks a lot!
Aleksey

Logicien · Posted: Thu May 17, 2012 5:58 am Post subject:

I do not use LVM. I don't know how it behave. You can try to pass the rw parameter to your Linux kernel to force it to mount the root partition as read write. A problem can occur if fsck have to work on boot. It will complain that the root partition is not read only. That can drop you to a shell or even worst. In that setup, /etc/fstab must not be configure to check the root filesystem. It's anyway just a workaround.
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Paul

lesha_n · n00b Joined: 15 Nov 2007 Posts: 65

Thank you, I tried out your suggestions, unfortunately nothing worked, still getting the same thing. Here is what I tried:

Booting with LiveDVD and editing /etc/fstab entry for my / to set the sixth field (fs_passno) to 0 to avoid running fsck on boot for the / partition
Passing rw option to the kernel

I do not think LVM matters, I just included that info for completeness (and / is not under LVM anyway).

My basic problem is that I cannot even see the boot messages, since the screen is very rapidly cleared when I get dropped to the shell. dmesg does not seem useful, and /var/log/messages does not seem to exist. How could I see the boot-up messages to get a clue of what's going on?

Does anyone have any idea what to try next?

Many thanks,
Aleksey

Logicien · Posted: Thu May 17, 2012 7:04 pm Post subject:

Tring to understand,

can you remount your root partition as read/write from the shell you get? That would make possible to work on the system. You can try to change the runlevel to 1 from the kernel command line, or from /etc/inittab to disable services and get administrative rights.
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Paul

slydini · Posted: Fri May 18, 2012 12:44 am Post subject:

The fact that /var was the one that needed repairs leads me to want to check the var directory very closely. Maybe the kernel is unable to write it's messages to /var/log. Check all the permissions on the directories and /etc/fstab should be similar to the /etc/fstab on a working system.

The hostname is not showing up in the login prompt and that info is in the /etc directory so check all of the related config files in there too. This always reminds me how important it is to have a backup on hand for just such an emergency.
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Oh how I love Linux, especially on gentoo.