VMware Changes the Playing Field
VMware's Player tool can make architectures you used to only dream of a reality. Our new Windows Insider columnist, Greg Shields, walks you through the possibilities as well as tips for increasing performance.
It was [Redmond's former Windows Insider Columnist] Bill Boswell's thoughtful
and engaging writing that originally attracted me to this magazine so many years
ago. So, is it a cliché to say that one can never replace him, only succeed
My name is Greg Shields, and the editors at Redmond magazine have
asked me to take over this column. In my day job I'm a systems administrator
for Raytheon Co., managing a network that's not too large and yet not too small.
I hope to use that experience in the middle ground, along with a few good stories,
to help make your job easier.
Land of the Free
Released in mid-December of last year and with one major exploit already announced
and patched, VMware's Player tool has taken the Internet by storm. A restricted
version of the well-known and full-featured VMware Workstation application,
the freely distributable Player brings the core functionality of VMware to the
masses at a very reasonable cost.
VMware Player won't allow you to build new virtual machines (VMs) or reconfigure
the hardware on existing ones -- you'll need VMware Workstation or a similar
app for that. But if you've created a compatible VM, the freeware Player license
suddenly opens a whole new realm of possibilities for leveraging VM technologies
in the workspace. Imagine a few of the architectural possibilities now available
that may have been previously financially unattainable:
- Movement of insecure or risky applications off the desktop. Having
a problem with users downloading spyware through their browser and corrupting
their desktop? Run IE or Firefox inside a virtual machine and configure the
VM to discard any changes every time it reboots. This way, if the user accidentally
downloads some nasty bug, the fix is little more than a reboot of the virtual
machine. If you're a Firefox user and want to try out this concept of a "browser
appliance,” VMware has a pre-built one already available on its Web site at
ww.vmware.com/ products/player, also for no cost.
- Applications that follow users between hot desks. A call center
environment comes to mind, with lots of employees switching between hot desks,
yet needing a stable work environment. Laptops too expensive? What about creating
and distributing pre-built workstations on USB thumb drives? As users move
from hot desk to hot desk, they merely plug and boot their thumb drive and
they've got the same comfortable desktop they used at their last station.
- Decoupling development environments from operational environments. Ever
worked with developers who can't, or won't, upgrade their code from Windows
2000? Still need to maintain a Windows NT environment for backward compatibility,
but don't have the funding for an entirely separate hardware infrastructure?
Install Player on every desktop. Now you can run your office automation and
e-mail applications on the host desktop, but segregate the development environment
tools to the virtual machine. You can also use this to eliminate those pesky
admin rights from all your developers' host machines, further securing your
An added benefit of this architecture is that developers gain more flexibility
to "upsize" the development server sitting at their desk to VMware's
ESX Server when it comes time for testing or code integration activities.
Make the RAM Salesman Happy
Of course, all this decoupling activity comes at a cost. Downloading and installing
VMware Player onto a sample machine and powering up the Firefox browser appliance
consumes about 200MB of RAM. Compare that to a typical Firefox instance run
directly from the host machine, where RAM consumption barely touches 20MB.
There's also a relatively large hit to processor performance because you're
essentially running two OSes, rather than one merely to run a single application.
So, any of the architectures I've mentioned will likely involve some investment
in hardware upgrades. You'll need to compare that increase in hardware cost
with the savings in time cost for system rebuilds when spyware infections occur.
There are a few things you can do to enhance VMware Player's performance. These
may sound like common sense, but because VMware is really just another system
running on your host system, they're particularly important.
- Defragment the host's disks as often as possible. Members of the
VMware community recommend doing so on a daily basis. With VMware's disk files
often consuming gigabytes of space for a single file, even a little fragmentation
can significantly impact performance.
- On systems with ample RAM, disable memory trimming. According to
information located at the highly useful blog site www.virtualization.info,
VMware regularly checks for unused virtual memory to return back to the host
OS. This permits more concurrent virtual machines, but incurs a performance
hit. Disable this by adding the line MemTrimRate=0 to the virtual machine's
- To reduce page file usage, VMware uses a page sharing technique that
allows guest memory pages with identical content to be stored as a single
copy-on-write page. This decreases host memory usage but consumes added
system resources. You can disable this by adding the line sched.mem.pshare.enable=FALSE
to the virtual machine's .VMX file.
- Disable anti-virus real-time scanning on .VMDK and .VMEM files. These
are the files that contain your VM's virtual disk and virtual memory. When
a VM is active and running, the vmware-vmx.exe process regularly reads and
writes to those files. If your anti-virus' real-time scanner has to scan every
read and write, it can slow down the effective performance of the virtual
- Create all virtual disks as "pre- allocated.” When a virtual disk
is created, the user has the option to increase the size of the disk as necessary
or create the maximum size of the disk all at once. By pre-allocating the
entire disk, the system doesn't incur the performance degradation associated
with re-addressing the additional space as the disk gets bigger, and the disk
is less likely to become fragmented in the process.
- For highly resource-intensive VMs, consider separating out the virtual
machine's physical disk drive from the drive with the system page file.
For even better performance, try three drives—one for the system disk, one
for the virtual machines and one for the page file. This alleviates disk spindle
contention during periods of high use.
Home of the Brave
Although VMware's licensing agreement allows for virtually unlimited deployment
within a company, and includes fairly liberal conditions for repackaging and
redistributing the technology into other applications, the company claims no
official support for the product. Digging into its Web site, however, shows
about 20 articles in the knowledge base and a fairly active and interesting
to the Masses
With VMware Player a zero-cost
tool, the hard part is getting it distributed to the unwashed
masses in your enterprise. Thankfully, VMware has built a
“silent” deployment mechanism into the tool that
will allow your SMS, Altiris or other deployment tool to easily
install it to desktops across the enterprise.
In order to silently install VMware, download
the most recent version from its Web site: www.vmware.com/download/player.
When configuring the installation, use the switches /s
/v/qn to run the install silently and install with
all defaults. Note that there is a space after
/s but no space between
/v and /qn.— G.S.
The company recognizes the enterprise deployment value in the product and upgrades
are on its radar. According to the company's Dec. 12 press release, "VMware
is planning to release a version of VMware Player that developers can easily
extend and customize in early 2006.”
So, it appears that VMware may indeed have changed the playing field. With
virtualization technology components now a computing commodity, the hazy line
between a "real” system and a "virtual” one is growing more and more obscure.