VMware vSphere virtual infrastructure administrators often need to increase the size of a VMDK virtual disk protected by VMware vSphere Replication technology. If you try to increase the disk from vSphere Client, then you will get this error:
Therefore, to increase the replicated VMDK disk, you need to do the following:
- Rename the folder with the virtual machine and virtual disk on the backup site. This is necessary so that when replication is disabled the folder (with the VM on the backup site) is not deleted.
- Remember the VM replication settings (RPO, datastore destination, etc.).
- Disable replication of the virtual machine.
- Increase the size of the virtual disk on the backup site from the vSphere Web Client GUI via Edit Settings.
- Now increase the size of the virtual disk on the main site using the vmkfstools utility. To do this run the command:
vmkfstools –X 500G virtual_machine.vmdk
- Then on the backup site, rename the folder with the VM back to the original name.
- Configure VM replication again by selecting ‘Specify datastore folder’ and the folder with the VM to be replicated.
- Click Yes and the replication will start.
If you do not increase the size of the virtual disk on the backup site, you will receive the following error message:
So do not skip this step. Further reading: KB 2052883