I have given 200MB of the space to /boot partition while creating the VM which is very less.
After some upgrades the /boot partition became out of space, because of this OS started crashing. One fine day i need to move this VM to another node i copied it using
command. Then the VM was not starting it gave the message as
kernel panic – kernel panic not syncing vfs unable to mount root fs on unknown-block 0 0 – error
started googleing the problem, what else i can do 😉 i came accross a blog where same issue is slove here.
he says the /boot partition is full, so need to remove old grub. because i dont want to increase hdd size.
1: Restart the vm or computer into the Grub2 menu then choose “Advanced options for ubuntu”
2: Once you go into the advanced boot menu you will likely see several kernels listed. Choose the next-oldest kernel from the top/highest version of kernels.
3: Open terminal and check your current kernel: from command
DO NOT REMOVE THIS KERNEL! Make a note of the version in notepad or something.
4: Next, type the command below to view/list all installed kernels on your system.
dpkg --list | grep linux-image
Find all the kernels that lower than your current kernel. When you know which kernel to remove, continue below to remove it. Run the commands below to remove the kernel you selected.
sudo apt-get purge linux-image-x.x.x.x-generic
sudo apt-get purge linux-image-extra-x.x.x-xx-generic
Finally, run the commands below to update grub2
Reboot your system.