Rocky Linux install not booting after recent update

Hi all, new to getting Linux support so forgive me if I am missing details.

My Rocky Linux install updated over night along with a reboot and I found it not responsive this morning. The VPS panel showed the CPU at 100% usage. It didn’t despond to anything but a power cycle.

On booting I noticed this error:
kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block

If I rebooted and selected the slightly older kernel it boots without issue. The currently running kernel is:
5.14.0-503.19.1.el9_5.x86_64

Happy to provide whatever details are needed, I just don’t know what they might be.

It could be a number of things like the initrd image is missing or malformed for the new kernel or the boot entry in /boot/loader/entries/<macineID>-<kernel-version> is deficient. You can generate a new initrd with dracut, see the man page, and with grubby you can check the boot entries.

In a terminal run this command:

sudo grubby --info=ALL

and compare each index for the lines “args=” and “root=” to see if the latest kernel is listed with the same parameters.

Let us know what you find. This has happened to me in the past. Is this a recent Rocky install?

I had the “same” issue with 5.14.0-503.19.1 and it got fixed with 5.14.0-503.21.1 again :+1:

1 Like

I rebooted into the normal kernel and got this.

If I power cycle and select the second option from the list it boots:

Yes this is a recent Rocky install, I did have an initial issue with some of my RAM missing. I did some troubleshooting and the kdump service was was not starting
kdump.service: Main process exited, code=exited, status=1/FAILURE

I went down a rabbit hole of troubleshooting but could never resolve it. I got “around” it by just disabling the kdump service. I only mention it since you asked if it was a recent rocky install.

Attaching as another post because the system stops new users from putting more than one image in a post apparently.


Booting from the second option works.

Sounds like the new kernel isn’t installed properly and the initramfs hasn’t been generated properly. You can try reinstalling the new kernel when booted using the older kernel. AS @jbkt23 already hinted at.

As requested.

[root@server~]# sudo grubby --info=ALL
index=0
kernel="/boot/vmlinuz-5.14.0-503.21.1.el9_5.x86_64"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-5.14.0-503.21.1.el9_5.x86_64.img"
title="Rocky Linux (5.14.0-503.21.1.el9_5.x86_64) 9.5 (Blue Onyx)"
id="5f5deafd908a4123b4d3b232000ffd8f-5.14.0-503.21.1.el9_5.x86_64"
index=1
kernel="/boot/vmlinuz-5.14.0-503.19.1.el9_5.x86_64"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-5.14.0-503.19.1.el9_5.x86_64.img"
title="Rocky Linux (5.14.0-503.19.1.el9_5.x86_64) 9.5 (Blue Onyx)"
id="5f5deafd908a4123b4d3b232000ffd8f-5.14.0-503.19.1.el9_5.x86_64"
index=2
kernel="/boot/vmlinuz-5.14.0-503.15.1.el9_5.x86_64"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-5.14.0-503.15.1.el9_5.x86_64.img"
title="Rocky Linux (5.14.0-503.15.1.el9_5.x86_64) 9.5 (Blue Onyx)"
id="5f5deafd908a4123b4d3b232000ffd8f-5.14.0-503.15.1.el9_5.x86_64"
index=3
kernel="/boot/vmlinuz-0-rescue-5f5deafd908a4123b4d3b232000ffd8f"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-0-rescue-5f5deafd908a4123b4d3b232000ffd8f.img"
title="Rocky Linux (0-rescue-5f5deafd908a4123b4d3b232000ffd8f) 9.5 (Blue Onyx)"
id="5f5deafd908a4123b4d3b232000ffd8f-0-rescue"
index=4
kernel="/boot/vmlinuz-5.14.0-427.16.1.el9_4.x86_64"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-5.14.0-427.16.1.el9_4.x86_64.img"
title="Rocky Linux (5.14.0-427.16.1.el9_4.x86_64) 9.4 (Blue Onyx)"
id="1d8642cea31a428c8dc1fefe9250df72-5.14.0-427.16.1.el9_4.x86_64"
index=5
kernel="/boot/vmlinuz-0-rescue-1d8642cea31a428c8dc1fefe9250df72"
args="ro console=tty0 console=ttyS0,115200 quiet vga=771 crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M"
root="LABEL=rootfs"
initrd="/boot/initramfs-0-rescue-1d8642cea31a428c8dc1fefe9250df72.img"
title="Rocky Linux (0-rescue-1d8642cea31a428c8dc1fefe9250df72) 9.4 (Blue Onyx)"
id="1d8642cea31a428c8dc1fefe9250df72-0-rescue"

I am beginning to think the two problems are related:

[root@server~]# sudo dracut --force
dracut: dracut module 'kdump' cannot be found or installed.

No matter what I did last time I couldn’t get kdump installed or the service running.