Extend the disk of an Ubuntu VM on VMware ESXi

Recently we had to extend the disk of an Ubuntu instance on vSphere ESXi 7. The task was not that easy and involved several steps. So, I thought of sharing the steps with you. Will look at the steps in brief. 

NOTE: Make sure to take a full backup of the system before attempting these steps. 

  • First of all, access the VM properties and extend the disk as necessary. 

  • Make sure the “parted” package has been installed. You could install the package using sudo apt-get install parted
  • SSH into the ESXi host and then access the relevant datastore which the VM is stored. 

cd /vmfs/volumes/datastoreX/UbuntuVM

List the files using ls -l

Then, use the vmkfstools command to extend the disk. In this example, vmkfstools -X 300G UbuntuVM.vmdk (300G is the extended size and never use the flat.vmdk for his operation)

  • After that login to the Ubuntu instance and extend the partition using sudo parted and then type to print the partition table
  • You will be presented with the partition numbers (pick the second partition [which is X])
  • Enter the command resizepart X to resize the partition. After that type Q to quit the partition utility. 
  • Finally, grow the file system using the command sudo resize2fs /dev/sdaX (X denotes the disk number)

You could verify the disk size using the command df -h

“Unable to apply DRS resource settings on host”

The above error can not be ignored and needs to be fixed. Otherwise, the cluster’s effectiveness can be drastically reduced. Will look at the fix in a nutshell. 

  • SSH into the host with root credentials and run the below commands (Host and vCenter agents)

/etc/init.d/hostd restart

/etc/init.d/vpxa restart

  • Then, restart all the management agents 

services.sh restart

  • Confirm whether both the Host and vCenter agent services are up and running. 

/etc/init.d/hostd status

/etc/init.d/vpxa status

This should fix the issue. But it will take 20-30 minutes to go away the alert.