(Solved) kernel panic - not syncing: vfs: unable to mount

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

Good afternoon all!

So the complete error was

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

My guess is: you didn't include the proper disk support in the kernel. With "old server" is hard to guess what that would be. Could be anything from pata/sata/scsi or any of the raids. My suggestion is boot again the live cd and analyze dmesg/lspci from there, not from your kernel which doesn't include the obvious support you need.

NeddySeagoon · Posted: Fri Jul 27, 2018 6:19 pm Post subject:

FrankRizz0,

unknown-block(8,4) tells the kernel major and minor device numbers that the kernel is trying to mount as root.
That's /dev/sda4.

That you get (8,4) tells that the kernel can see something there but not understand what it finds.
Maybe the root filesystem driver is missing from the kernel?
Unless you have an initrd, <M> won't work.

Perhaps the live kernel and install media don't agree on what /dev/sda4 is?
As the box is/was a NAS, it will have several drives.

Grub lets you edit the in memory copy of the boot stanza ... press 'e' and do same trial and error.

Maybe you used a USB stick as install media and its still plugged in?
On some systems USB storage devices are enumerated before HDD?
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

Thanks for the reply Neddy. I removed the drives from the box besides one additional drive. I did the install using the LiveDVD on a USB stick, and also made sure to change it back to boot from the hard drive. Not exactly sure what you mean by <M>. Also, I'm unsure regarding pressing 'e', are you referring during the boot process to press e?

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

a total of 20 =m in the config. no way in hell it is the initrd file. Take a look at sata. Only has piix.

He said it's an old server. Has xeon. Certainly has a server type disk controller instead of piix.

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

Thanks for your help axl. Below is the output of dmesg:

https://paste.pound-python.org/show/uB4L5XRXa8HzxPsJ5RpL/

and I found some strange inconsistencies:

NeddySeagoon · Posted: Fri Jul 27, 2018 7:46 pm Post subject:

FrankRizz0,

When the grub menu appears, choose the option you want but press the 'e' key, not enter.

If you have a part of the SCSI stack missing, the error is usually unknown-block(0,0).
The <M> refers to the kernel menuconfig symbol means that something is to be made available as a loadable module. <*> indicates that the code is to be included in the kernel binary.

It matters because booting is solving the problem of loading an operating system from disk, on a computer that can read exactly one disk block. There are lots of circular dependencies to be broken.
Consider the following. There is a loadable module required to mount the root filesystem. The module is on the root filesystem, therefore it cannot be loaded until root is mounted.
There are two solutions build a kernel that can boot without needing loadable module support, or provide the modules in a temporary root filesystem, which is what an initrd is.

Tell us how you made your kernel.

Put your lspci output into a post.

Using wgetpaste, put your kernel .config file onto a pastebin site and post a link to it.

Tell us which filesystem types you have on which partitions.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

My lspci -k located here:

https://paste.pound-python.org/show/s2ekNk0mJA1ZDy0VngeW/

And my kernel config is here:

https://paste.pound-python.org/show/ntWMUViLVcjHkSSt3Qbb/

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

My fstab is located here:

https://paste.pound-python.org/show/zhMT46SMRHb0lmfhwW7S/

I did find an error with fstab, sdb is actually ext4 not 3, but this wouldn't cause my system not to boot.

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

Almost forgot, how I built my kernel; I researched what I could from lspci -k output and used google.

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

I have no clue. Afaik it should have worked. For my own curiosity could you post the output (while on live dvd) of udevadm info -a -n /dev/sda pls ?

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

https://paste.pound-python.org/show/jrwdeNUwGm04wQAIM1F3/

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

Thank you. Yes, as expected nothing special. SD disk is on, ext4 is on, ahci is on. Really have no clue.

At this point, If this would happen to me, I would start to wonder if I am booting the kernel I am compiling.

The only question mark I have left based on what you posted is what is on sda1?

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

U mentioned at one point you tried to treat the system as uefi.

combine that with a vfat first partition on a mbr disc that might include a previous iteration of kernel... and u have prolly your sda1. am I right?

EDIT what I am saying is that the kernel booted from sda1 is not the kernel from /boot on sda2. or kernel compiled on sda4 doesn't get on sda2. either way... that's what i would look at.

Marlo · Veteran Joined: 26 Jul 2003 Posts: 1591

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

axl you misunderstood, I did not try and build it as a uefi, it was already on the system, so the previous owner tried to install Gentoo and was unsuccessful (I know this because I have researched this system, it is definitely NOT uefi, it is bios). Marlo, sdb would not stop the system from booting. Further to this, yes, I did create a file in /home called Media.

Edit: Sorry, I did not create a user called Media, that is where I mounted sdb.

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

Possibly, I did not comment sda1 in fstab, maybe that will do the trick (I don't remember ever commenting grub as sda1 in fstab).

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

FrankRizz0 · l33t Joined: 29 Nov 2006 Posts: 617

OK so I think I somehow created sda2 as efi:

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

Like I said in a previous post, I think (bet/gamble 80% sure at this point), the kernel in efi / (slash) boot sda2 is not the kernel you compiled. sda3 is not swap. the whole thing is gpt without a point because is not larger then 2tb. and bios is not uefi.

save everything. make a single partition in mbr or whatever disk layout you like... but certainly not this. and make sure the kernel that has the config you posted is the kernel that is booted, and i'm 80% sure it will work.

axl · Veteran Joined: 11 Oct 2002 Posts: 1146 Location: Romania

i mean, for a bios/mbr setup, your partition layout is pretty weird. I would start over. save all data tar/xz. treat everything like a stage3 i want to save, instead of restore.

repartition the disk in a mbr manner, according to your requirements. and just start over with the save as stage 3.