A.5 Change Guardian Appliance goes to Emergency mode while rebooting

Rebooting the Change Guardian 5.2 Appliance in Hyper-V causes it to go into emergency mode. This occurs because the operating system modifies the disk UUID during installation. Perform the following steps to overcome this:

  1. Login to the Change Guardian 5.2 Appliance in emergency mode with root credentials.

  2. Run the command ls -l /dev/disk/by-id/ and note the actual UUID of the disk.

  3. Run the command cat for each of the following files to identify the disk UUID entries therein:

    • /etc/fstab

    • /etc/default/grub

    • /boot/grub2/grub.cfg

  4. Compare the actual disk UUID entries in /dev/disk/by-id for the SCSI partitions with those in each of the above files.

  5. If the disk UUIDs in each of locations do not match the actual values, you must manually replace the incorrect values with actual values.

    Example A-1 Modifying Disk UUIDs

    If the UUID entry in the fstab, grub or grub.cfg files is 14d53465420202020f21b50e22267274c823e145500a372b7, but the UUID on disk is 360022480f21b50e22267145500a372b7, there is a mismatch which you must manually correct.

    Therefore, once the UUID entry is replaced with correct values in the fstab, grub and grub.cfg files respectively, the entries therein read as below:

    • /etc/fstab

      /dev/disk/by-id/scsi-360022480f21b50e22267145500a372b7-part1 / ext3 acl 1 1

    • /etc/default/grub

      GRUB_CMDLINE_LINUX=" root=/dev/disk/by-id/scsi-360022480f21b50e22267145500a372b7-part1 nomodeset quiet"

    • /boot/grub2/grub.cfg

      linux /boot/vmlinuz-4.4.131-94.29-default root=UUID=ace9acb3-ac2b-47f0-960d-5b7cd5b51b47 root=/dev/disk/by-id/scsi-360022480f21b50e22267145500a372b7-part1 nomodeset quiet

  6. Reboot the VM.

  7. The SCSI disk partition UUIDs are detected correctly and the appliance boots normally.