Kernel panic at restart after so update

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raffaele.fabbri
Posts: 79
Joined: 2015/03/14 07:57:15

Kernel panic at restart after so update

Post by raffaele.fabbri » 2015/04/03 12:48:05

After update my centos7 at startup
Kernel panic not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

what can I do to start the system?

Thank's in advance

Raffaele
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TrevorH
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Re: Kernel panic at restart after so update

Post by TrevorH » 2015/04/03 12:51:51

Interrupt the boot when you see the grub menu and select the older kernel. Once up, check that the newer kernel has a corresponding initramfs file in /boot and if not then either run dracut to create one or yum reinstall kernel-3.whatever
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raffaele.fabbri
Posts: 79
Joined: 2015/03/14 07:57:15

Re: Kernel panic at restart after so update

Post by raffaele.fabbri » 2015/04/03 13:27:37

Thanks for your reply

what does it mean "check that the newer kernel has a corresponding initramfs file in /boot and if not then either run dracut to create one"?

thanks

giulix63
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Location: UK

Re: Kernel panic at restart after so update

Post by giulix63 » 2015/04/03 14:50:34

Say that the target kernel is 3.10.0-229.1.2.el7.x86_64:

Code: Select all

[root@localhost ~]# ll /boot/initramfs*
-rw-rw-r--. 1 root root 40803085 Mar 13 08:50 /boot/initramfs-0-rescue-13bfe39d2e7c48efa95ed6d6868f7c19.img
-rw-r--r--. 1 root root 15228904 Mar 13 10:39 /boot/initramfs-3.10.0-123.20.1.el7.x86_64.img
-rw-r--r--. 1 root root 16628981 Apr  1 09:56 /boot/initramfs-3.10.0-229.1.2.el7.x86_64.img
In this case, it is the last line. If it wasn't there, I would create it with:

Code: Select all

dracut /boot/initramfs-3.10.0-229.1.2.el7.x86_64.img 3.10.0-229.1.2.el7.x86_64
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raffaele.fabbri
Posts: 79
Joined: 2015/03/14 07:57:15

Re: Kernel panic at restart after so update

Post by raffaele.fabbri » 2015/04/03 18:14:43

Thanks for your reply

I don't found file with the version 3.10.0-229

[root@localhost ~]# ll /boot/initramfs*
-rw-r--r--. 1 root root 40817483 3 nov 07.40 /boot/initramfs-0-rescue-5fda862fa7a34e649abcedd607abafdf.img
-rw-r--r-- 1 root root 17621878 10 dic 21.18 /boot/initramfs-3.10.0-123.13.1.el7.x86_64.img
-rw-r--r-- 1 root root 17983497 10 dic 21.25 /boot/initramfs-3.10.0-123.13.1.el7.x86_64kdump.img
-rw-r--r-- 1 root root 17602012 19 dic 16.23 /boot/initramfs-3.10.0-123.13.2.el7.x86_64.img
-rw-r--r-- 1 root root 17988779 20 dic 09.53 /boot/initramfs-3.10.0-123.13.2.el7.x86_64kdump.img
-rw-r--r-- 1 root root 17582059 30 gen 21.56 /boot/initramfs-3.10.0-123.20.1.el7.x86_64.img
-rw-r--r-- 1 root root 17971887 30 gen 22.00 /boot/initramfs-3.10.0-123.20.1.el7.x86_64kdump.img
-rw-r--r-- 1 root root 17634533 16 nov 17.00 /boot/initramfs-3.10.0-123.9.3.el7.x86_64.img
-rw-r--r--. 1 root root 17969978 8 nov 21.46 /boot/initramfs-3.10.0-123.9.3.el7.x86_64kdump.img
-rw-r--r-- 1 root root 17603484 24 mar 20.46 /boot/initramfs-3.10.0-123.el7.x86_64.img
-rw-r--r-- 1 root root 19661725 3 apr 15.50 /boot/initramfs-3.10.0-123.el7.x86_64kdump.img

there were I yum pending that I have stopped with command sudo yum-complete-transaction

and then i started a new update but there where some conflicts as reported on the attached file

soumplis
Posts: 1
Joined: 2015/04/06 00:22:26

Re: Kernel panic at restart after so update

Post by soumplis » 2015/04/06 00:25:51

Same problem here with no luck reinstalling the kernel or running dracut manually to recreate the initramfs . I have seen this behaviour to several servers that have been upgraded from CentOS 6 but in non of the few with fresh CentOS 7 installations.

jakeb
Posts: 1
Joined: 2015/04/08 23:16:14

Re: Kernel panic at restart after so update

Post by jakeb » 2015/04/08 23:22:05

Systems upgraded from 6 to 7 may still be using grub instead of grub2, and 3.10.0-229.1.2 isn't adding an initrd line to grub.conf, as a workaround you can add initrd /initramfs-3.10.0-229.1.2.el7.x86_64.img to grub.conf manually after the kernel line, or upgrade to grub2.

SteffanCline
Posts: 2
Joined: 2015/04/17 13:29:13

Re: Kernel panic at restart after so update

Post by SteffanCline » 2015/04/17 13:42:25

I too ran into this issue yesterday. The new kernel was installed but I hadn't rebooted to see the issue yet. It seems that the rpm that installed the new kernel did not install the complete kernel config into grub.conf

Code: Select all

[root@mhloans grub]# cat grub.conf.broken
default=0
timeout=10
title CentOS Linux (3.10.0-229.1.2.el7.x86_64) 7 (Core)
  root (hd0)
  kernel /boot/vmlinuz-3.10.0-229.1.2.el7.x86_64 console=hvc0 xencons=tty0 root=/dev/xvda1 ro LANG=en_US.UTF-8
title CentOS Linux (3.10.0-123.20.1.el7.x86_64) 7 (Core)
  root (hd0)
  kernel /boot/vmlinuz-3.10.0-123.20.1.el7.x86_64 console=hvc0 xencons=tty0 root=/dev/xvda1 ro LANG=en_US.UTF-8
  initrd /boot/initramfs-3.10.0-123.20.1.el7.x86_64.img

... older kernel info ...
Notice the initrd line is missing with the .229 kernel. I'll try putting that in and rebooting to see if it solves the problem but have to wait until an off peak time on the server.

johanvermeij
Posts: 31
Joined: 2015/11/25 10:36:18

Re: Kernel panic at restart after so update

Post by johanvermeij » 2016/05/30 09:44:16

The new thing is that you now get notifications that updates are pending and you tend to just take that, same as with Apple..

Normally I am quite happy with what is there for what I am using in Centos.

I just did a yum update and the kernel panics as described, can't mount root fs.

I can boot the previous kernel but I would like to rollback the yum update.

Is that possible ?

johanvermeij
Posts: 31
Joined: 2015/11/25 10:36:18

Re: Kernel panic at restart after so update

Post by johanvermeij » 2016/05/30 10:05:49

I have installed Centos 7 fresh some time ago on a Acer Aspire E5-471-39Y1

Everything is working except the touch pad.
The wifi was problematic but I managed to compile the driver, all ok now.

So I can never forget my mouse when I have to go for a presentation.
I had to run to a PC shop to buy a mouse once before.

I actually do a yum update from time to time to see if the touch pad is working.

I develop software for Centos servers so I prefer to use a Centos client as well.

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