Kernal Panic - Not syncing : VFS: unable to mount root fs on unknown-block (0,0)

June 20, 2018 152 views
DigitalOcean CentOS

After rebooting the server I am getting Kernal Panic - Not syncing : VFS: unable to mount root fs on unknown-block (0,0) error, and not able to access it. Any suggestion to fix it quickly? It's a production server having 150+ websites and all of them are down now.

1 comment
  • I too have this problem. WTH Centos...

    Were you able to fix it?

1 Answer

Yes, finally I was able to fix it.

  • I am having same problem with centos when I tried to update it but failed some packages due to low memory and i am stuck now. Can you explain how did you solve? I tried to change kernel but all in vain

    • You need to boot your droplet using Digitalocean's recovery iso, here are the steps to do it https://www.digitalocean.com/docs/droplets/resources/recovery-iso/

      After that, you can mount the file system and choose the option to chroot, so you can switch to centos file system. next option is to switch the kernel of centos to recovery kernel and boot again with the original HDD and remove the kernel and install it again.

      • Sorry to annoy you but did you use same exact procedure given in the link to fix it? I don't know the commands for option 6 of /bin/bash. This is my live production server so can't bear HDD corruption

        • What I suggest is to first create a snapshot of HDD to safeguard your data, the same steps wouldn't work for you as the case is kernel related not the filesystem.

          If you want me to look over this, I can do this work for you.

          • I did these steps successfully until this point

            After that, you can mount the file system and choose the option to chroot, so you can switch to centos file system.
            

            but i don't understand how to do this

            next option is to switch the kernel of centos to recovery kernel 
            

            i changed kernel from digitalocean control panel to DigitalOcean GrubLoader v0.2 (20160714) CentOS

          • omfg tysm you're god in human form

            here is what i did which i think fixed it:

            • Mount file system
            • chroot
            • yum reinstall kernel
            • change boot sequence back to HDD
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