Bowulf Infosec & Network Admin Blog

VmWare ESX 2 vs. Microsoft Virtual Server

We had a meeting today with our local Microsoft pre-sales engineer particularly since we announced plans to base an upcoming project is based around VMWare ESX 2. Here were my impressions on the product not yet quite completely pressed yet. This is nothing revolutionary, but a simple first impression based upon VM-Ware knowledge and playing with Preview edition, which was nothing more than what they had got from Connectix. It has apparently be recoded significatntly since that release.

Price: $500-1000 for Virtual Server, as opposed to $3800 for 4 Proc VMWare box. One thing these numbers do not highlight is the necessity to buy the Host OS in the Virtual Server example. Adding $1580 for a Windows 2003 Enterprise Edition server CAL brings the difference closer. A closer match would be the VMWare GSX (its direct competitor), which weighs in at $2379 at CDW.

Playing the Support game: "We only support virtual guest OS'es under our virtual server software, but we do not under VMWare" is a bit disingenuous and beneficial to Microsoft. On that same note, VMWare does work hand in hand with Microsoft just as IBM does if we had an issue on IBM hardware. A possible mitigation factor would be a dissimilar hardware restore to rule out VMWare being an issue when the call to Microsoft was made. A simple reminder: I believe we had two calls to Microsoft support this past year on two mission critical servers, and we can't remember the last time we called Microsoft on test or development server, which is our current candidate for virtual servers. Major OEM's, like Dell and IBM, have teamed with VMWare to provide that software support as well.

SMP support- Virtual Server does not support Symmetric Multi-Processing (2 CPU's) on the guest OS side. This is a huge negative in my opinion as we go forward. How are we supposed to emulate a production environment that has multiprocessors on a VM that can only handle one to the guest OS?

Performance: Due to the presence of a host OS and everything running within that host OS, the performance on the Virtual Server is only 75-80% according to Microsoft. VMWare ESX2 runs within its own kernel (i.e. no Host OS to impact performance numbers), and its performance is near physical server. (92% is the number we had in class in web server get retrieves and disk performance testing.) Adding to the performance numbers is the ability to run a greater number of VM's at the same time due to how it uses memory for the VM's. Even though Microsoft doubts the capabilities (probably because they can't do it yet), it would allow for a greater (over allocation) of memory with proven technology.

Software maturity: While Microsoft protests to contrary, this is a public 1.0 product. It has never been deployed outside Connectix and Microsoft for more than a month, and while I have high regard for their testing procedures. 1.0 product releases to enterprise customers scare me more than anything. Other products, like their Physical 2 Virtual product, are even less mature and have not even been released yet. Their preview release in their words was not even the final RTM product, so here is one bleeding age product that I would be slower to deploy.

Networking - Not relevant for right now, but the VMware has been strenuously tested by ICSA (the firewall testing org) and was approved by them to be used as enterprise firewall.

Training - Having most of the team trained already on their workstation products and myself being trained on ESX 2, I believe the VMWare product has a definite advantage in that department.

This is just only on the service evaluation so far without personal knowledge of the final copy (which hasn't officially been released yet) of Virtual Server or the ESX2 (not workstation) product outside of training. I am certainly willing to try both products and make a more informed decision based upon actual in-house data and first hand knowledge of both products. I also failed to mention many of the other benefits (scripted OS installs, 64 bit CPU support, support for VLANs) that Virtual Server does not have at this point. I just wanted to make sure I avoided any misconceptions of what I had said or heard today.