After update, kernel panic at boot with error: Unable to mount root fs on unknown-block(0,0)

Solution Verified - Updated -


  • After a fresh install and reboot, or after a kernel update, the system fails to boot with the following message:

    VFS: Cannot open root device XXX or unknown-block(0,0)
    Please append a correct "root=" boot option; here are the available partitions:
    Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
    Call Trace:
      [<ffffffff81527213>] ? panic+0xa7/0x16f
      [<ffffffff81c27432>] ? mount_block_root+0x216/0x2cb
      [<ffffffff81002930>] ? bstat+0x2b0/0x980
      [<ffffffff81c2753d>] ? mount_root0x56/0x5a
  • OS unable to boot after kernel upgrade on RHEL 7

    alt text

  • When upgrading the system (and the kernel in the process), the server doesn't reboot anymore.


  • Red Hat Enterprise Linux 5
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

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