grub.conf missing initrd path after kernel update

Question

I updated a server this morning and the latest kernel panics during boot. Upon review of the grub.conf file I found the initrd path was missing. Is there a way to fix this issue? Or should I remove the most recent kernel entry from grub.conf and boot from the previous kernel (tested working)?

grub.conf file:

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/mapper/vg_spots-lv_root
#          initrd /initrd-[generic-]version.img
#boot=/dev/vda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-431.20.3.el6.x86_64)
    root (hd0,0)
    kernel /vmlinuz-2.6.32-431.20.3.el6.x86_64 ro root=/dev/mapper/vg_spots-lv_root rd_LVM_LV=vg_spots/lv_root rd_LVM_LV=vg_spots/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet
title CentOS (2.6.32-358.14.1.el6.x86_64)
    root (hd0,0)
    kernel /vmlinuz-2.6.32-358.14.1.el6.x86_64 ro root=/dev/mapper/vg_spots-lv_root rd_LVM_LV=vg_spots/lv_root rd_LVM_LV=vg_spots/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet
    initrd /initramfs-2.6.32-358.14.1.el6.x86_64.img

I found this link explaining how to re-build the init file. Rebuild Initrd

Not totally understanding all the risks, would this be a good idea to try? This is a production server and I don't want to take it down completely. :)

If it fails to boot in a VPS/EC2 instance where you don't have arrow keys, mount it to another instance and edit the file to change `default=1` and it will select the 2nd entry. — Chloe, Jun 05 '17 at 16:41

score 4 · Accepted Answer · edited Jun 05 '17 at 18:30

4

You can just add the initrd back in yourself.

initrd /initramfs-2.6.32-431.20.3.el6.x86_64.img

You should check your /boot directory and ensure that it is actually present.

To fix it permanently for future upgrades, run

# yum reinstall kernel.x86_64

edited Jun 05 '17 at 18:30

Chloe

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answered Jul 03 '14 at 16:19

Michael Hampton

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Doesn't exist... Looks like rebuild might be my only option. – prodigerati Jul 03 '14 at 16:25
Just reinstall that particular kernel with `yum reinstall` then. It should rebuild the initrd. – Michael Hampton Jul 03 '14 at 16:31
2

Yum reinstall did the trick! Thank you! `yum reinstall kernel-2.6.32-431.20.3.el6` – prodigerati Jul 03 '14 at 16:55
The generic form `# yum reinstall kernel.x86_64` also works. – Chloe Jun 05 '17 at 16:39

score 1 · Answer 2 · answered Jul 03 '14 at 16:26

1

If you can boot into one of the older kernel versions, see if you can run update-grub to fix the issue. Otherwise, as Michael said, you can just add the entry in by hand supposing the actual initrd file exists.

answered Jul 03 '14 at 16:26

Unix-Ninja

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grub.conf missing initrd path after kernel update

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