Slim Down and Speed Up VMs with VM Optimizer
With this handy tool, your Windows VMs will be smaller and run faster than ever.
Many IT pros are faced with maintaining a virtual machine library or
with having to package and take VMs on the road. One problem with maintaining
a large amount of VMs on a computers hard disk or with copying VMs
to removable media is the size requirements of virtual hard disks. A typical
Windows Server 2003 basic installation in a VM, for example, consumes
about 3GB of disk space.
If you have several VMs or environments consisting of multiple VMs, then
optimizing the amount of storage space required by each VM is probably
very important to you. If thats that case, you should take a look
In my test lab, I recently used VM Optimizer to slim down the Windows
Server 2003 VM that I use as a baseline image for each Microsoft Virtual
Server VM that I manage. Before using VM Optimizer, the VM consumed 2.9
GB of storage space. After completing the optimization process, the VMs
virtual hard disk was reduced to a gig. I then zipped the optimized Windows
2003 VM and was able to reduce it to only 345 MB, which allows the VM
to be copied to a CD-ROM, as well as consumes a lot less storage space
on the servers hard disk.
VM Optimizer supports several virtualization platforms, including Microsoft
Virtual Server and Virtual PC, VMware Server, VMware Workstation and Virtual
Iron, and can optimize Windows 2000 and newer guest operating systems.
VM Optimizer works by removing unneeded files and disabling unnecessary
programs and services. Among the optimizations that are performed:
- Stop and disable unnecessary services
- Unistall MSN
- Remove unnecessary files (temp, log, autorecover, help, service pack
and Windows Update cache)
- Defragment the virtual hard disk
While its true that you could manually do most of VM Optimizers
changes on your own, its low price ($129 for the single user corporate
edition) may have you asking yourself the question Why would I want
Using VM Optimizer is pretty straight forward. Basically, once you download
the software and install it, youll have a CD-ROM ISO image file
that contains the VM Optimizer program. To optimize a VM, you just need
to mount the VM Optimizer ISO image file to the VM as a virtual CD-ROM
drive, and with auto-run enabled in the VMs guest OS, VM Optimizer
will start once the CD is mounted.
VM Optimizer includes two unique CD-ISO builds: automated and manual.
The automated version requires no user intervention. As soon as the VM
Optimizer CD mounts to the virtual machine and auto-run launches VM Optimizer
within the VMs guest OS, the optimization process will automatically
start and run to completion. With the manual version of VM Optimizer,
youll have the ability to navigate through a wizard and select the
specific optimizations that you would like performed.
Figure 1 shows available optimizations for a Windows 2003 guest OS. My
preference is to use the manual optimization so that I can choose exactly
what VM Optimizer removes or disables.
[Click image to view larger version.]
|Figure 1. Selecting the optimizations for VM
Optimizer to perform
Once the optimization completes, you will need to click Finish in the
VM Optimizer dialog box and the VM will automatically shut down. To recover
the virtual hard disk space that was freed by VM Optimizer, you will need
to perform an offline compaction of the virtual hard disk file. You can
compact Virtual PC or Virtual Server vhd files by following these
steps on the Invirtus Web site. VMware .vmdk virtual hard disk file
compaction instructions are available here.
Note that you will not see a disk size reduction when compacting fixed-size
or pre-allocated virtual hard disk files. In order to recover space from
a fixed-size or pre-allocated virtual disk files, you first need to convert
them into dynamically expanding virtual hard disks. Details on compacting
fixed-size virtual hard disks are available in my Tech Line column, Virtual
Disk Compaction Confusion.
If you have several Windows VMs that you need to shrink and optimize,
then you should definitely take a look at Invirtus VM Optimizer. If your
storage devices could clap, they would probably loudly applaud the purchase.
About the Author
Chris Wolf is VMware's CTO, Global Field and Industry.