Bug 19460 - Kernel-panic VFS:Unable to mount root fs on unknown-block(0,0)
Summary: Kernel-panic VFS:Unable to mount root fs on unknown-block(0,0)
Status: RESOLVED OLD
Alias: None
Product: Mageia
Classification: Unclassified
Component: RPM Packages (show other bugs)
Version: 5
Hardware: i586 Linux
Priority: Normal normal
Target Milestone: ---
Assignee: Kernel and Drivers maintainers
QA Contact:
URL:
Whiteboard:
Keywords: NEEDINFO
: 17966 (view as bug list)
Depends on:
Blocks:
 
Reported: 2016-09-26 19:13 CEST by Bjarne Thomsen
Modified: 2018-09-20 08:37 CEST (History)
3 users (show)

See Also:
Source RPM: kernel-server-4.4.22-1/i686, grub2
CVE:
Status comment:


Attachments
journalctl -ab > NOcrash.txt an OK boot after a panic (107.61 KB, text/plain)
2016-09-28 14:07 CEST, Bjarne Thomsen
Details
journalctl -ab -1 > panic.txt (157.99 KB, text/plain)
2016-09-28 14:11 CEST, Bjarne Thomsen
Details
/boot/grub2/grub.cfg (9.36 KB, text/plain)
2016-09-28 15:57 CEST, Bjarne Thomsen
Details

Description Bjarne Thomsen 2016-09-26 19:13:16 CEST
Description of problem:
Kernel-panic VFS: Unable to mount root fs on unknown-block(0,0)
But it works fine when I boot in recovery mode.

Version-Release number of selected component (if applicable):
kernel-server-4.4.22-1 (i686)

How reproducible:
Always

Steps to Reproduce:
1.
2.
3.
I am mounting root on a btrfs.
Is this a problem?
Marja Van Waes 2016-09-27 10:43:32 CEST

CC: (none) => marja11
Assignee: bugsquad => kernel

Comment 1 Thierry Vignaud 2016-09-27 11:24:11 CEST
Could me a missing initrd
What bootloader are you using?

Keywords: (none) => NEEDINFO
CC: (none) => thierry.vignaud

Comment 2 Bjarne Thomsen 2016-09-27 12:48:52 CEST
I forgot to mention that the same thing happened to
kernel-server-4.4.21-1
But then shortly after came kernel-server-4.4.21-2
and the default boot worked again.
I have now made soft links from 4.4.21-2 to
vmlinuz-server
and
initrd-server.img
and I am now booting from 4.4.21-2.
grub2
Thierry Vignaud 2016-09-27 12:55:34 CEST

CC: (none) => zen25000
Assignee: kernel => bugsquad
Source RPM: kernel-server-4.4.22-1/i686 => kernel-server-4.4.22-1/i686, grub2

Comment 3 Marja Van Waes 2016-09-27 13:27:10 CEST
What is the output of

ls -al /boot | grep initrd
Comment 4 Bjarne Thomsen 2016-09-27 20:24:09 CEST
-rw-r--r-- 1 root root 10203324 Sep 20 22:33 initrd-4.4.21-server-2.mga5.img
-rw-r--r-- 1 root root 10202648 Sep 25 05:09 initrd-4.4.22-server-1.mga5.img
lrwxrwxrwx 1 root root       31 Sep 27 05:51 initrd.img -> initrd-4.4.21-server-2.mga5.img
lrwxrwxrwx 1 root root       31 Sep 27 05:50 initrd-server.img -> initrd-4.4.21-server-2.mga5.img

I did change the links this morning.
But now I have just tried to boot specifically
4.4.22-server-1
and it worked! I do not understand what is going on.
I am going to create the original links.
Comment 5 Bjarne Thomsen 2016-09-27 20:45:00 CEST
I used the MCC to re-create the boot loader.
It crashed again when doing a default boot.
But, as before, it booted fine when I specifically
selected the 4.4.22-server kernel in the boot menue.
-rw-r--r-- 1 root root 10203324 Sep 20 22:33 initrd-4.4.21-server-2.mga5.img
-rw-r--r-- 1 root root 10202648 Sep 25 05:09 initrd-4.4.22-server-1.mga5.img
lrwxrwxrwx 1 root root       31 Sep 27 20:27 initrd.img -> initrd-4.4.22-server-1.mga5.img
lrwxrwxrwx 1 root root       31 Sep 27 20:27 initrd-server.img -> initrd-4.4.22-server-1.mga5.img

So, what is the difference from the previous case?
Comment 6 Bjarne Thomsen 2016-09-28 08:31:55 CEST
It does NOT reproduce! This time it crashed when I
specifically selected the 4.4.22 kernel.
Recovery still works.
Comment 7 Marja Van Waes 2016-09-28 10:31:31 CEST
So, regardless of whether kernel 4.4.22 is booted as default, or booted because manually selected: sometimes there's a kernel panic and other times there isn't.


Please reproduce the crash and then boot up again with the _same_ kernel-server-4.4.22, until it doesn't crash and you can log in.

Then, as root, do:

  journalctl -ab > NOcrash.txt

and 

  journalctl -ab -1 > panic.txt

and attach both files to this bug report.

Assignee: bugsquad => kernel

Comment 8 Marja Van Waes 2016-09-28 10:33:44 CEST
the second command might not do what I want: if it was impossible to mount /, then no logs were written :-(
Comment 9 Bjarne Thomsen 2016-09-28 14:07:35 CEST
Created attachment 8458 [details]
journalctl -ab > NOcrash.txt an OK boot after a panic

I have never seen a correct boot after letting it boot by itself.
To obtain a correct boot I moved many times betwen "Mageia" and "Advanced options"
before I finally pressed "Mageia".
Is this a timing problem?
Comment 10 Bjarne Thomsen 2016-09-28 14:11:17 CEST
Created attachment 8459 [details]
journalctl -ab -1 > panic.txt

This journalctl took about 20 m.
Comment 11 Marja Van Waes 2016-09-28 14:37:35 CEST
(In reply to Bjarne Thomsen from comment #10)
> Created attachment 8459 [details]
> journalctl -ab -1 > panic.txt

Most likely from the one-but-last succeeding boot, as I feared (i don't see a crash)

> 
> This journalctl took about 20 m.

I don't understand, what exactly took 20 minutes?

Those logs start at Sep 28 13:04:14 and end at Sep 28 13:16:26, the end time is slightly more than two minutes before the last succeeding boot log (which starts at Sep 28 13:18:42)

I assume the kernel panic boot was in between 13:16:26 and 13:18:42?
Comment 12 Thierry Vignaud 2016-09-28 14:40:58 CEST
journalctl won't help here indeed as the boot process hangs before mounting /
Can you attach your /boot/grub2/grub.cfg file?
Comment 13 Bjarne Thomsen 2016-09-28 15:57:32 CEST
Created attachment 8461 [details]
/boot/grub2/grub.cfg
Comment 14 Bjarne Thomsen 2016-09-29 13:00:08 CEST
I have installed the desktop i686 version of 4.4.22 on 3 old netbooks
with 1GB and 2GB of memory. These 3 i586-systems boots fine using grub2.
The system with the boot problem is an Intel MB with 8GB of memory,
so the server kernel was selected.
Note: The grub2 boot works with 4.4.21-server-2.
Comment 15 Marja Van Waes 2016-09-29 15:42:10 CEST
Just noticed that you filed bug 17966 for the same issue, with earlier kernels.

That wasn't what I was looking for, though, I thought someone had switched all his 32bit kernel-server installs to 64 bit installations. If he filed a bug report, then I'm looking over it.

I'll close that one, because this one contains more recent information
Comment 16 Marja Van Waes 2016-09-29 15:43:29 CEST
*** Bug 17966 has been marked as a duplicate of this bug. ***
Comment 17 Bjarne Thomsen 2016-09-29 16:12:43 CEST
I had forgotten about this old report.
The reason is that it went away after an update.
Comment 18 Bjarne Thomsen 2016-11-02 18:13:14 CET
It works now with kernel-server-4.4.30-1.mga5
Comment 19 Bjarne Thomsen 2016-11-05 06:54:45 CET
I am sorry, this bug is back again with kernel-server-4.4.30-2.mga5.
Comment 20 Bjarne Thomsen 2016-12-07 00:32:47 CET
As usual
kernel-server-4.4.36-1.mga5 boots korrectly, however
kernel-server-4.4.36-2.mga5 gives kernel panic.

what is actually done between *-1 and *-2 ?
Comment 21 Bjarne Thomsen 2017-03-31 08:30:33 CEST
History repeats itself. New kernals have booted correctly until now.
This bug is now back in
kernel-server-4.4.59-1.mga5
Comment 22 Bjarne Thomsen 2017-07-12 19:34:35 CEST
Actually I a solution. I keep one kernel installed, only.
After the next kernel install I remove the old kernel.
Now, this problem never happens. I have no idea why.
Comment 23 Marja Van Waes 2018-09-20 08:37:11 CEST
(In reply to Bjarne Thomsen from comment #22)
> Actually I a solution. I keep one kernel installed, only.
> After the next kernel install I remove the old kernel.
> Now, this problem never happens. I have no idea why.

Do you still need to do that in Mageia 6, to avoid hitting this bug?

If so, then please reopen this report and change Version: to 6

Closing as OLD, because Mageia 5 is no longer maintained at all.

Resolution: (none) => OLD
Status: NEW => RESOLVED


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