How to Grow a VMware VM Disk and Extend Its Partition

First, expand the virtual disk. In VMware Workstation, power the VM off and remove all snapshots. You can then use the graphical interface, through Edit Virtual Machine Settings > Hard Disk > Utilities > Expand, or the command line, with something like vmware-vdiskmanager -x vm.vmdk to resize the VMDK file.

On ESXi, log in to the host or the vSphere Client, edit the VM settings and increase the size of the virtual hard disk there. Save the changes to apply the new capacity.

Second, extend the partition inside the guest OS. Once the virtual disk is bigger, the extra space shows up in the VM as unallocated storage. On a Windows VM, open Disk Management, right-click the partition next to the free space and choose Extend Volume, then finish the wizard.

Before you resize, check that:

The VM is powered off.

All snapshots are deleted.

A backup exists, in case something goes wrong.

That preparation lowers the risk of corruption and keeps the expansion straightforward.

Q1: Why can't I expand the disk when snapshots exist?

VMware blocks a resize while snapshots are active. Remove them all first.

Q2: Why does the guest OS still show the old disk size?

You still have to extend the partition inside the guest OS after expanding the virtual disk.

Q3: Is a reboot required after resizing?

Sometimes, particularly when the guest OS does not notice the new storage on its own.

Q4: Should I back up before resizing a disk?

Yes. A resize carries risk, so take a backup first.