VMware launches free version of ESX3i

09 Aug 2008 by Simon Haslam (in Virtualization)

Just when the Xen-based virtualization products (like OracleVM) seem to be gaining ground, VMware recently made an interesting move by announcing a free version of ESXi (see VMware ESXi page).

For readers not too familiar with x86 virtualisation, products like VMware Server and Microsoft Virtual PC sit on top of an operating system, whereas ESX and Xen runs directly on the hardware (so called "bare metal" hypervisors). The latter approach has the benefit of offering near-native performance, improved security and better management.

Last year VMware launched ESXi, a "stripped down" version of their hypervisor. This has comparable performance to ESX but has a minimal service console (you manage it remotely) and is small enough to fit in flash memory. This has allowed manufacturers to offer disk-less servers that just boot into ESXi from an internal USB memory stick (e.g. see HP integrated hypervisor paper) which I think has many advantages (but more about my ideal server hardware another day!).

Now, if you're reading this blog, the chances are that you're an Oracle App Server/Fusion Middleware administrator, and are probably wondering why you should care about this systems admin stuff! Well, there are several reasons:

• As a technology, x86 virtualisation is maturing very quickly. Potential cost savings through increased hardware utilisation means that, whether we like it or not, I think most of us will probably have to work with virtual servers within the next 5-10 years (rather like SAN/NAS technology was...).
• Virtual servers are very useful for creating test environments. This is expecially true for middleware as you can quite frequently have an OAS HA cluster of 4, 6 or 8 servers. Such clusters can be expensive to replicate in a test environment, especially if you want more than one of them!
• Even if you ignore the high-end HA and DR features, virtual servers can be very handy for backup especially prior to an upgrade. As application servers generally aren't that big by modern standards it is quick, and doesn't take that much disk space, to backup or snapshot them.
• From a consulting perspective I've been running VMware Server environments for at least a couple of years now and find it very helpful to be able to not only create comparable test installations, but also to be able to easily save and restore such environments. For production administrators there's an equivalent: often you have a very stable, mature application on its own server that hardly get touched and so doesn't justify a proper pre-production environment; such a system could be held on a virtual server somewhere and only powered up on the rare occasions that it is needed.

So, even if you or your systems administrator are not familiar with virtualisation, you can hopefully see that it is worth evaluating for middleware servers at least. 

There are currently still some practical drawbacks though, sadly both of them Oracle-related:

1. Support: Oracle has only relatively recently started supporting virtual environments and that is only on Oracle VM (a Xen derivative). If you run into a bug when running on, say, RHEL on ESX you have to recreate it on a non-VM environment to prove it first.
2. Licensing: Oracle doesn't yet recognize software partitioning as a means of dividing processors on a server. Therefore you have to buy licences according to the number of physical processors, not what you're using in a particular VM.

Note that platform independence has historically been one of Oracle's strengths so I'm hoping that, with customer and analyst pressure, soon they will provide support for VMware-based environments too.

Finally, for those virtualisation-sceptics out there, and I was one of them once(!), I hope I've whetted your appetite... check back here for ESXi adventures over the coming months!