Increase size of VMWare virtual disk

Let us have a look at how to increase size of VMWare virtual disk.

Apparently there are several ways of increasing the disk size on a VMWare VMDK file, so below I will describe the way I have successfully done this in my virtual environment (vSphere 5.1).

(Note: This kind of operation can be harmful to your virtual machines and this information is provided without ANY warranty or responsibility for what happens when you do it! Make sure you have a proper backup before you engage in these activities)


First of all you need to have access to VMware ESXI Shell as described in my previous post.

After this we can start the work to expand our VMDK file.

Step 1 is to locate the VMDK file

  1. Log in to the VMware ESX/ESXi host as the root user.
  2. Run vim-cmd vmsvc/getallvms to list the location of the configuration files for the virtual machines registered on an ESXi host.
  3. Record the location of the .vmx file (configuration file) for the virtual machine that you are looking for. For example:/vmfs/volumes/46b2f3eb-ced4c7d8-c1d2-111122223333/vm1/vm1.vmx
  4. The results of step 4 list all virtual machine configuration files. Search the results for the name of a virtual machine file you are interested in locating. The results also list the path to the directory where these files are located.
  5. By viewing* the configuration file of a virtual machine, you can tell where all of its associated files, including .vmdk files, are located. If a file is not in the same directory as the configuration file the complete path is shown in the configuration file. For example, a second hard disk may have an entry such as the one shown below:scsi0:1.present = “true”
    scsi0:1.fileName = “/vmfs/volumes/46b2f3ea-980a1c90-3333-00112233bb44/diskStore/secondHardDisk.vmdk”

    • *Tip: Use the VI editor to view the content of the VMX file

    This information is based on this article from vmware :

Step 2 will be actually expanding the file.

Virtual disks can be expanded using this ESXi/ESX command line command vmkfstools -X:

vmkfstools -X <new size> <virtual disk>.vmdk

Here is an example, use this command to grow the virtual disk to 25GB in size:
vmkfstools -X 25g /vmfs/volumes/xxxx/vmname/vmname.vmdk

  • Changes are made to the disk and are almost instant.
  • Partitions residing within the virtual disks will not resize and there will be unallocated space at the end of the disk.Third-party partitioning tools are required at this point to resize the primary partition to take advantage of the additional space.
  • VMware Converter allows you to specify a new disk size in its conversion wizard. It will also take care of partition resizing for you.


You can read more details on this if you need it here