VMware Server for Linux for Free
I will turn down free beer software in favor of freedom software when both exist. If you don't know the difference, that's OK. You cannot see the source code for the video drivers from ATI, for example. You can get them for free but they are not freed. The same with Adobe Acrobat Reader and plugins for the Firefox web browser.
When it comes to virtual machines for Linux I reach a dilemma. Luckily, I have the free VM for Linux, Xen, running a DNS server on my web site. I say luckily since many people of whom I know cannot get Xen to run.
I also have VMware running on another host on our network for testing purposes. Though I don't have access to the source code for VMware, I have decided to drink a six pack and admit this bud's for me.
In my opinion, Xen's a pain and needs what many free software applications need: a frontend. While our friends at Novell have put some serious time into making Yast something of a frontend for Xen, I can't get it to work. But then, I have many other complaints about SUSE as well, so I have come to expect poor engineering decisions at that company.
VMware has a mature, well-engineered and versatile console for its server product. I hesitated to try it until contracted to do a comparison for a book. Now, I'm sold, even though I got VMware server for free.
Features to consider
Here's a couple of paragraphs from VMware's web site that's worth quoting:
Virtualization allows multiple virtual machines, with heterogeneous operating systems to run in isolation, side-by-side on the same physical machine. Each virtual machine has its own set of virtual hardware (e.g., RAM, CPU, NIC, etc.) upon which an operating system and applications are loaded. The operating system sees a consistent, normalized set of hardware regardless of the actual physical hardware components.
Virtual machines are encapsulated into files, making it possible to rapidly save, copy and provision a virtual machine. Full systems (fully configured applications, operating systems, BIOS and virtual hardware) can be moved, within seconds, from one physical server to another for zero-downtime maintenance and continuous workload consolidation.
I found truth in VMware's claims. We setup a test environment under a single IP address. Several developers used that environment. What they did not know: I had multiple VM instances available for each developer and changed them as needed. So, host3, became an environment for testing web development, smtp configurations and administrative scripts.
At one point I had to change the Linux distribution for the host machine. I compressed each instance, put them on an optical storage medium and decompressed each of them after I completed the installation of the guest OS. The process worked flawlessly.
Now, I'm starting to think about the VMware model for free applications like DHCPd, OpenLDAP, etc. I know some frontends exist for those, but I find them lacking and inflexible.
With the number of web developers in the free software community, I'd like to encourage an effort from them to consider writing web enabled frontends for applications like OpenLDAP. I'm not suggesting writing Gnome or KDE applications. Those come with too much overhead.
But, a web enabled console for OpenLDAP running on Debian sans X makes some sense. I have seen such a beast, but the company that developed it wants too much money for it. It's also coupled with a groupware server made up of free software turned proprietary.
What irks me about that company? They use free software to construct their product and you don't see a single bit of code published. They call it their IP and that doesn't stand for Internet Protocol.
What's the cost of leaving our best applications faceless? Adoption. While I may like the CLI functionality of OpenLDAP, enterprises don't. If Xen Source wants to sell what VMware gives away for free, then let them do it. But, I can't support Xen Source with a good conscience.
While I've seen their management console, I consider it just another piece of proprietary software built on the shoulders of the free software community. Good luck Xen source. I'm encouraging my friends to take a look at VMware server.