Category: IT Support

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 P 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

“Extend Volume” greyed out

Recently, one of my friends got back to me saying that he could not extend the C drive. Upon checking, we figured out that the “Recovery” partition was sitting between the System partition and the Unallocated space.

Basically, the “Recovery” partition was blocking the feature. In order to fix this, we had to delete the “Recovery” partition. Will look at how we can fix the issue in a few simple steps. 

[Note: all the commands are in Bold Italic]

Step 01: Open an elevated command prompt and enter diskpart

Step 02: Select the relevant Disk and list the partitions 

select disk 0

list partitions

Step 03: Upon confirming, select the recovery partition (in my case, it is Partition 3)

Step 04: After selecting the correct partition, delete the partition. delete  partition  override

Step 05: Extend the volume using either the command extend or disk management in GUI.