[SOLVED] System wont boot

dalgrim · 10-10-2015, 07:36 AM

I had my video card fail in my system and had to replace it. In the process of doing that I had to update my bios to support the new card. This of course cleared my settings. I changed everything back to what I had but now my slackware 14.1 system will not boot.
The final error gets cut off but what I can see is:
"Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(8,18)"
"Comm: swapper/0 Not tainted 3.10.17 #2"

I am able to boot from the slackware14.1 DVD and mount the drive and read all contents. I also forced a fsck -F on that drive and it is fine. I am using the default huge kernel from initial install. I tried making an initrd and that didn't help. I re-ran lilo and still get the exact same error.

*My window7 partition still boots fine... eww

I'll post a 10 second vid I took on my phone of the boot process.
edit: Video
http://www.dalgrim.com/files/slack/20151010_080420.mp4
edit2: images of just before death

http://www.dalgrim.com/files/slack/2...080907_012.jpg
http://www.dalgrim.com/files/slack/2...080907_013.jpg
http://www.dalgrim.com/files/slack/2...080907_014.jpg

-Brian

Emerson · 10-10-2015, 07:43 AM

It is looking for root on sdb2, is this where your / is?

dalgrim · 10-10-2015, 07:46 AM

Quote:

Originally Posted by Emerson

It is looking for root on sdb2, is this where your / is?

yes this is where it is, well it should be....

I'll verify. I didn't touch the partition tables on the drive. I'll edit this in 5 min with a result.

-Brian

Didier Spaier · 10-10-2015, 08:04 AM

Output of these commands, typed from the DVD installer (just after logging in as "root") could help investigate:

Code:

mount /dev/sdb2 /mnt # chek if /mnt is your installed system's /)
lsblk -o model,name,fstype,mountpoint,size
cat /mnt/etc/fstab
cat /mnt/etc/lilo.conf

PS you could store the results on a mounted USB key.

dalgrim · 10-10-2015, 08:22 AM

ok, so my hard drives for reordered.

sda and adb got swapped in the BIOS update it seems.

I updated lilo.conf to:
http://www.dalgrim.com/files/slack/lilo1.jpg
http://www.dalgrim.com/files/slack/lilo2.jpg

Here is my fdisk

http://www.dalgrim.com/files/slack/fdisk.jpg

A note on my setup:
I have a marvell 9128 controller for the now "sda" drive, sdb is in IDE mode and is an older sata2 3gbs drive. I have lilo installed to that drive.

I'll reboot again and get the results of "cat etc/fstab" but I'm guessing that I'll have to fix that now that I know the drives got swapped.

even with the updated lilo conf with
boot=/dev/sdb
#Linux
image=/dev/sda2

It still doesn't boot, giving the exact same kernel panic error at the end
(maybe the fstab)

What I did do:
booted from DVD
mkdir /mnt/hddsda1
mkdir /mnt/hddsda2
mount /dev/sda1 /mount/hddsda1
mount /dev/sda2 /mount/hddsda2

a quick "ls" in /mnt/hddsda2 shows that it is my linux partition
I did a chroot /mnt/hddsda2
everything looked correct there /etc/lilo.conf is what I posted in the images.

I'll reboot now and get the fstab file and post it.

Thanks for the quick responses!

-Brian

Emerson · 10-10-2015, 08:30 AM

Do not use IDE mode. It was meant only for Windows users to enable Windows boot and installing AHCI drivers.

dalgrim · 10-10-2015, 09:04 AM

Quote:

Originally Posted by Emerson

Do not use IDE mode. It was meant only for Windows users to enable Windows boot and installing AHCI drivers.

I changed the second drive to AHCI. *the marvell one already was

This improved the situation. now it'll get 1/2way through the boot before giving a bad superblock error:
http://www.dalgrim.com/files/slack/newerror.jpg

I enter the root password and it enters singleuser mode:

trying to run fsck gives this error:
http://www.dalgrim.com/files/slack/newerror2.jpg

Didier Spaier:
here is the command output you asked for:
http://www.dalgrim.com/files/slack/lsblk.jpg

*after seeing this I did change the /dev/sda to sdb / and changed what was sdb to sda

-Brian

Didier Spaier · 10-10-2015, 09:16 AM

Quote:

Originally Posted by dalgrim

Didier Spaier:
here is the command output you asked for:
http://www.dalgrim.com/files/slack/lsblk.jpg

Well, two remarks:

In the output of lsblk I see that you have an ext4 file system on /dev/sda2, so there lies your Linux / partition, but in /etc/fstab /dev/sda2 is supposed to be your swap partition and / is supposed to be mounted on /dev/sdb2 that is actually a swap partition. This is inconsistent and can't work.
I don't see the point in putting / and swap on two different disks. But maybe that doesn't hurt.

dalgrim · 10-10-2015, 09:29 AM

Quote:

Originally Posted by Didier Spaier

Well, two remarks:

In the output of lsblk I see that you have an ext4 file system on /dev/sda2, so there lies your Linux / partition, but in /etc/fstab /dev/sda2 is supposed to be your swap partition and / is supposed to be mounted on /dev/sdb2 that is actually a swap partition. This is inconsistent and can't work.
I don't see the point in putting / and swap on two different disks. But maybe that doesn't hurt.

It seems the disks got reordered when I had to flash my BIOS. The system was on sdb2 before. ugh It looks like I missed updating that fstab line for my swap partition. I'll update that and try again to boot.

The reason the swap is on another drive is just a space issue. The / drive only has 146GB space. so I put the swap on the other slower drive. I have 12GB RAM anyways so Swap should rarely be used.

I'll update if fixing that fstab entry for swap fixes the problem.

-Brian

Emerson · 10-10-2015, 09:38 AM

In case you need to run fsck do it from a liveCD and make sure the filesystem you are checking is not mounted.

dalgrim · 10-10-2015, 10:01 AM

Yay, it's working, for the most part.

I don't know why my BIOS decided to renumber the hard drives but after the lilo.conf edit and fstab changes the system boots now.

You guys all rock, I'm in awe of the knowledge on this forum. Thanks!

-Brian

bassmadrigal · 10-13-2015, 06:36 AM

It might be worth looking into converting your lilo.conf and fstab.conf to using UUIDs instead of the locations. UUIDs only change when you reformat the drive and won't be affected by changing computer hardware/bios. This would've prevented your problem completely.