Hi,

My linux system fails to boot after a blip in the power. Upon boot it jumps to a grub screen, which if I select advanced options I get
*Ubuntu 18.04.6..... with Linux 4.15.0-189-generic, and the same kernel with recovery options.
Hitting the recovery, gives a kernel boot that ends very early with a 'Kernel panic - not syncing: timer doesnt work through interupt remapped IO-APCI'

I dont really understand what this means or how to get a system that has been fine for the last year working again!

Any help really appreciated

Thanks

nick

Welcome to the forums!

Is there another kernel you could try?

Generally, you should boot from an external media and run fsck on all your filesystems. Also I'd run smartctl test on hard drive. Then further decisions can be made depending on outcome. Perhaps the drive is dying and needs to be replaced, in this case you should make sure your backup is current and replace the drive. It may be the drive is OK and the power outage caused filesystem corruption, in this case the easiest may be reinstall or restoring from backup if you have full backup made. There may be other ways, for instance booting from external media, chrooting into your system and reinstalling kernel. It all depends on what got corrupted and why, is it only power outage related or the drive is also failing.

1 members found this post helpful.

Hi Emerson,

Thanks for taking the time to help!

I have booted to the live usb distro which can see and mount the disk. Running fsck on the disk comes up with it being 'clean'. Looking around I found a post that recommended something called 'testdisk' which takes a deeper look this also found no problems. Not quite sure what else to look for, corrupted grub file?

nick

Going back to the panic, that is APIC mode not being enabled (in BIOS). I wonder if the power outage disabled APIC mode?

One can boot with the noapic option on the grub line to avoid this but a modern computer should have APIC mode but the panic is definitely a mismatch of grub options and BIOS apic mode.

Hi,

Thanks to both of you for taking the time to provide helpful advice

My box is a 2011 dell optiplex, that does not support apci, but various bios tweaks for power management.

The bios settings all looked ok but I decided to reset to defaults any way. This then enabled the recovery kernel to run, after which the standard kernel came up.

So not quite sure if the bios had an issue or whether fsck/testdisk fixed something, end result is I am a happy chappy again

Regards

nick