The first release candidate (RC1) for VMware Server is out. VMware Server is VMware’s free virtualization product. It requires either Windows or Linux as the operating system and installs itself as an application/daemon/service which you can run on your private machine.

VMware Server 1.0 was more or less the GSX server revamped and released to the public for free. It was quite slow and had some problems keeping up with the Linux kernel release cycle. As the application requires some kernel modules to be built it is dependent upon the kernel source. The kernel source can differ quite a lot from release to release and will therefore break the module building process from time to time. For those of use which are either living in the “bleeding edge” world or are patching regularly due to security problems, this turned out to be a major problem.

VMWare Server 2.0 have been a much nicer experience, at least for me. The modules are no longer a problem since VMWare have released beta 1, beta 2 and now RC 1 in accordance with the Linux kernel release cycle. The performance issues are mostly resolved too since 2.0 is using larger parts of ESX internally. Or, I can not say that for sure, but the config files suggests that 2.0 is using ESX components.

So, why would anyone pay for ESX or ESXi when you can get Server for free? Well, the first problem is manageability. ESX and ESXi can be managed from VirtualCenter Infrastructure where you can add your whole data center and play around with the machines. The status for Server 2.0 RC1 is that you only can use the VirtualCenter Infrastructure Client to manage a single host at the time. You have to connect directly to the server running VMware Server to manage it.

Ocourse, in VMware Server you have to do all the iSCSI magic in Linux instead of letting VMware handle it. There are no support for VMotion, DRS or HA either. So, VMware Server is not an enterprise class application.

Another problem is that you have to maintain an operating system in addition to VMware Server. By being dependent on an operating system which is not tailored for the hypervisor you also get some more overhead. This means that you will have fewer resources available for the virtual machines.

But, VMware Server is quite fun to play around with. It is actually perfect for my storage server which runs Linux instead of ESX because I need access to it by SMB, NFS and iSCSI at the same time.

So, quickly summarized: VMware ESX & ESXi for your production servers, VMware Server (hey, it’s free!) for your single server at home. Or, naturally, if you are on a budget :-)