This article will explain how to fix the upgrade issue due to a corrupted /etc/default/grub file.

The upgrade will fail with the error as per the below screenshot:

We will see the below error from paches.log under /var/log/setup- during the cliniq test:
 

Dec 6 13:05:49 2013: Grub Files Check

Dec 6 13:05:49 2013: Ensures grub files and settings are correct

Dec 6 13:05:49 2013:   [FAILURE]

Dec 6 13:05:49 2013:     File /etc/default/grub has an unexpected value for the field

Dec 6 13:05:49 2013:     'GRUB_SERIAL_COMMAND'. This field is expected to have the following

Dec 6 13:05:49 2013:     keys: '--unit=', '--speed=', '--word=', '--parity=', '--stop='

Dec 6 13:05:49 2013:    [REMEDIATION]

Dec 6 13:05:49 2013:     <None Provided>

In the file /etc/default/grub, there will be a duplicate entry "GRUB_SERIAL_COMMAND="serial".

We need to remove the entry by taking the backup of the file to any other directory.

Here is the sample output of the file /etc/default/grub:

GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_DISABLE_RECOVERY="true"
GRUB_CMDLINE_LINUX="crashkernel=auto console=ttyS0,9600 console=tty1"
GRUB_SERIAL_COMMAND="serial --unit=0 --speed=9600 --word=8 --parity=no --stop=1"

After making the change, please do the upgrade again

If you are still facing the same issue, please contact JTAC for assistance