In last week's article, we discussed virtualization and its role in reducing server sprawl. We included VMware server as one of the products used to virtualize a data center. VMware also sells a workstation with a well-established reputation. This week we take a look at VMware Workstation 5.0.

In the past, many analysts have given kudos to VMware workstation for aiding people who want to run different operating systems for development and testing. Some even have claimed that the product accelerates application deployment. Similar suggestions abound about VMware workstation allowing Windows users to play around with Linux without having to format their hard drives.

Journalists who rely on VMware to evaluate and write about Linux on their Windows laptops, however, will never understand the power and sophistication of Linux. VMware Workstation has many uses, but it is not a substitute for a native Linux installation on bare hardware. Reviewers who practice using VMware to evaluate Linux do themselves and the community a great disservice.

Still, VMware workstation has a value proposition and in certain instances, it can give Linux users some help. For example, in previous articles, I have used the example of a major telecommunications company that migrated to Microsoft Exchange while forgetting that 30% of their users had UNIX and Linux desktops. The CIO's solution included buying 30,000 laptops for $4,000 a piece, simply to run Microsoft Outlook.

Ultimately, the company reprovisioned those laptops and added Citrix servers and VMware to the engineers UNIX and Linux workstations, respectively. Although still an expensive proposition, the company realized a considerable cost savings by trading the laptops for VMware and Windows.

VMware Workstation is a $200 software application that creates virtual machines and allows someone to use some Linux or Microsoft Windows desktops to host other operating systems. For Linux users, it provides a way to run Windows on their workstations provided they have an acceptable distribution. According to VMware, Workstation version 5 runs on:

To view all the supported Linux operating systems, you should visit this link. VMware supports older Linux hosts in addition to those mentioned above.

Keep in mind you might feel confused by the differences in the release notes and the specifications on the VMware Web site. If you believe the Linux hosts available are limited to the ones listed as newly supported in the release notes, you may miss out on the ability to run older Linux distributions as hosts. Figure 1 shows a screenshot of VMware Workstation 5 installed on a Novell Linux Desktop (NDL9).

Figure 1. The Start-Up Screen for VMware Workstation 5

I had some difficulty finding a suitable host for VMware workstation. Although the release notes claim that the software runs on SUSE Pro 9.2, it didn't. In fact, I kept getting this error message:

None of the pre-built vmmon modules for VMware Workstation is suitable
for your running kernel. Do you want this program to try to build the
vmmon module for your system (you need to have a C compiler installed
on your system)?

CC [M] /tmp/vmware-config1/vmmon-only/linux/driver.o 
/bin/sh: scripts/basic/fixdep: No such file or directory 
make[2]: *** [/tmp/vmware-config1/vmmon-only/linux/driver.o] Error 1 
make[1]: *** [_module_/tmp/vmware-config1/vmmon-only] Error 2 
make[1]: Leaving directory `/usr/src/linux-2.6.11.4-21.7' 
make: *** [vmmon.ko] Error 2 
make: Leaving directory `/tmp/vmware-config1/vmmon-only' 
Unable to build the vmmon module. 

I decided to try SLES 9 in the form of Novell Linux Desktop and installed it without any updates. VMware did install on the original version. Afterward, I updated NDL 9 and tested VMware Workstation 5 and it continued to work.

You also may find some confusion on the VMware site regarding which Linux distributions can operate as "guest" systems and which operate as hosts. Just remember the host provides space for the guest.

Guest operating systems include:

Because I run Linux as my host, I'm not exactly thrilled by the options provided by VMware 5--users have two Mandrake options as well as older SUSE and Red Hat and RHEL options from which to chose. You can find no Debian Linux options, and Fedora isn't supported. The Linux guests lack some excitement too. A glimpse of the list shows that VMware hasn't provided the journalists any state-of-the-art Linux distributions about which they can write.

VMware Workstation 5 allows multiple operating systems and applications to run at the same time on a single physical computer. If you have a lot of RAM, a large hard drive and a serious CPU, VMware performs okay. In this way, it is more of a developer's product than an end-user one.

The guest operating systems live in isolated virtualized machines. VMware maps a hosts computer's hardware resources to the virtual machine's resources, so each virtual machine has its own CPU, memory, disks and I/O devices, so to speak. Each virtual machine appears to the guest operating systems as a standard x86 computer.

Once VMware Workstation installs a guest operating system on the host, you can install and run unmodified versions of Windows, Linux, Novell NetWare and Sun Solaris x86, as well as applications written for those platforms, on one machine. VMware says users can see the benefit of using multiple PCs without the expense, physical setup and maintenance of various hardware platforms. By the time you build a machine with enough resources for the guests to operate at acceptable level, you could have saved money buying separate PCs. But VMware has other advantages at which we should look.

Figure 2 provides a look at VMware Workstation running on NLD 9 with Windows XP Home Edition installed. This should give you an idea of what you can expect to see if you use this product. Notice on the top of the tool bar that an icon lets you select a full-screen mode. By selecting this option, the guest occupies all of your monitor's pixels. It's still not going to give you the benefit of a great visual experience, however.

Figure 2. Windows XP Home Edition Running on NLD 9

The virtual hardware of VMware 5 runs better than previous versions. With a single Pentium IV or an equivalent AMD processor and 512MB of RAM, one should be able to run two virtual machines simultaneously. The previous versions would grind to a halt in such a scenario.

I wouldn't recommend running your system that way, however. If you have a need to run more than one virtual machine, you should run dual high-end processors and 3GB of memory. Otherwise, you cannot use your host machine and the two virtual machines with any efficiency.

Snapshots of an OS

Version 5 provides for multiple snapshots so a user can take a snapshot at any point and revert to its original or another state when a guest is powered down. Users can configure a virtual machine to take a snapshot when a guest is powered off and preserve an audit trail. If you need to examining a virus, for example, you can take a snapshot before you introducing the malware. If you the virus does damage, a user can restore the virtual machine to the state preserved in that snapshot. The same goes for testing new code or a patch.

Previous versions of VMware allowed for the taking of snapshots. However, once you created a second one, it would overwrite the original snapshot. So, for testing purposes, version 5 provides a significant upgrade.

Virtual Networks

Workstation teams allow users to set up a virtual network or lab on a host computer. You can power up multiple virtual machines as mentioned above. You then can configure networking the way you would on any local area network, however, this network would run on a single computer.

Users can work together in what VMware calls a LAN segment. They are invisible to the host computer's network, which creates the possibility of doing development in a virtual safe house.

Cloning

The new VMware Workstation provides interesting deployment capabilities with what the company calls clones. In VMware workstation terms, two types of clones exist. One it called a full clone, which we might consider to be similar to a ghosted image used to provision another computer. The second type of clone is called a linked clone. It remains dependent on the original image.

VMware's full clone functions as an independent copy of a virtual machine. Once a user makes the clone, it runs separate from the parent. It then can go off and become a unique instance that you can use to make changes or deploy for whatever purpose you see fit.

VMware's linked clone shares virtual disks with the original or parent, conserving disk space. This permits multiple virtual machines to use the same software installation. Also, linked clones take less time to create than a full clone does.

Labs might want to create linked clones to provision to developers, quality assurance engineers, testers or maintenance programmers--literally for different tasks. By storing a linked virtual machine on your local network, other users quickly can make a linked clone. A support team can reproduce a bug in a virtual machine, and an engineer quickly can make a linked clone of that virtual machine to work on the bug.

The files on the parent of a linked clone continue to exist at the time one creates a snapshot and continue to remain available to the linked clone. Changes to the parent don't affect the linked clone, and changes to the disk of the linked clone do not affect the parent.

If you have followed the progress of VMware since it started up, you may have thought of it as a way to use Windows applications on your Linux desktop. I know I did. That seemed like the founders' intentions. But, we cannot really know what vision or roadmap the company had.

VMware workstation ceases to have relevance in terms of a way to deploy Windows applications as Linux begins replacing those applications with native versions that run in GNOME, KDE and other desktop environments. The future for VMware lies in the server area, where it has given Linux a leg up in the data center. One can only wonder how much longer the workstation will continue to have a market.

Regardless, VMware has served an important place in the history and evolution of free Linux. Many people still love it and are glad it's around. Hopefully, the company y will innovate and make using Windows applications simpler for Linux users while they grow their server business.