It has been observed that the root disk throws Kernal panic error as below on a hardware after upgrading to v7.5.1.
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Check the current default index using the following command.
grubby --default-index
It should be 0 by default. Check the current default kernel:
grubby --default-kernal
Check the OS name using the following command:
grubby --info=ALL
Take note of the index ID for the OS from which the OS is currently being booted up.
Change the default index of the OS using the following command:
grubby --set-default-index=<ID>
Here, update the <ID> with the actual ID of the OS, such as 1 or 2. Then, verify the default configuration after applying changes.
grubby --default-index
grubby --default-kernal
After a reboot, the appliance should boot up from the changed order and OS.
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