Best practice: Before you begin extending the VMware virtual disk, create a backup copy so that you can restore it in case of failures.

Extending a virtual disk can be a complex operations for several reason, e.g.,:

1) Windows Primary Partition

The virtual disk that is full happens to contain the boot/primary partition for Windows. The following post will help you build intuition about resizing partitions.

• The Ultimate Guide to Hard Drive Partitioning

2) Snapshots

Eric Seibert’s posts describe the complexity introduced by snapshots.

• How VMware snapshots work
• Deleting virtual machine snapshots without wasting disk space

3) Disk space constraints

There is insufficient disk space available on the physical drive to permit further growth

4) Complex multi-step process

It is a multi step process and involves use of different tools and commands in a specific sequence. Creative individuals have devised workarounds to extend the primary partition for Windows by using Linux boot disks and disk partitioning tools such as GParted, and you have to get this right. Here’s an excellent post describing several different approaches.

• Re-sizing Virtual Disks by by Eric Seibert

Recovering from failures to extend: When things go wrong, it can be very painful. Here are a few real-life experiences to learn from

• Help, please, cannot start VM after changing HD size with vdiskmanager GUI
• Unable to clean up deleted files: The specified virtual disk needs repair.

Windows on Mac: Mac users feel particularly challenged in dealing with the Windows philosophy, arcane commands and foreign behavior. Look at few Mac forums and you will realize how tough life can get for them

• Expanding the Hard Drive Space on VMware Fusion

Introducing fatVM: fatVM lets you extend the C drive of your VMware Fusion or VMware Workstation’s virtual disk safely and reliably when it becomes full. fatVM provides a simple, intuitive, interface and a reliable process that hides the technical complexity of extending a virtual disk. It is a robust solution that supports extension of virtual disks that have snapshots and clones. You can use fatVM with full confidence because it safely preserves your original disk, which remains available to you in case the need ever arises.

Download fatVM.