VMware Virtual Infrastructure 3 review

Virtual Infrastructure 3 (VI3) is the latest suite of enterprise grade server virtualisation tools from virtualisation specialist VMware. It enables a single server to simultaneously run multiple operating systems. With a dedicated hypervisor to manage the virtualisation and support for server hardware with up to 32 logical CPUs and 64GB of RAM, it's the most scalable server virtualisation platform currently available.

New features in VI3 include the ability to take up to 32 snapshots of each virtual machine (VM), support for 64bit VMs, and support for VMs with up to four CPUs and 16GB of RAM.

The VI Starter Edition consists of the company's flagship ESX Server 3 virtualisation platform, which runs on Intel and AMD x86 based servers. However, the Starter Edition cannot use SAN storage, cannot be installed on a server fitted with more than four CPUs or 8GB or RAM, and does not support VMs with more than one processor. Also, the Starter Edition does not support VMotion - a feature that enables VMs to be moved from one ESX host to another without rebooting the VMs or disconnecting their users.

Although we have installed ESX Server onto hand built server systems, VMware does not support such configurations. Instead it publishes lists of compatible server, SAN, and I/O hardware. It's important to check this list, but generally speaking mainstream server kit from popular manufacturers would be fine. Relative to ESX 2.x, the Starter Edition is much reduced in price, costing $1,000 per two processors, compared to around $5,000 for ESX 2.x.

For deployments in organisations with only one ESX Server, the Starter Edition is a good choice. Like all the VI3 products, it includes an agent for connecting the ESX Server to VMware's VirtualCenter management console, which is sold separately. Priced at $3,750, the mid-range VI Standard Edition includes virtual SMP so VMs can be configured to use up to four virtual processors. However, most firms will also want the high-end features such as Dynamic Resource Scheduling (DRS) and High Availability (HA), which are available only when the Enterprise Edition is combined with VirtualCenter, a combination that will currently set you back over $8,000. Added to these prices, firms must also budget for mandatory maintenance contracts, which cover minor software upgrades, bug fixes and technical support via a toll free number with a 4 hour response time during business hours. For example, the minimum support option for the Starter Edition costs $675.

We reviewed VI Enterprise Edition, which costs $5,750, and comes with the DRS and HA features enabled. However, without a second Enterprise Edition ESX Server to run these against, the features are largely redundant in a single ESX Server environment.

Planning

Although the features available in ESX 3 and the VI3 package are attractive, firms upgrading an existing ESX 2.x server system need to plan the upgrade carefully. For example, VMs on the target server must all use version 2.x virtual hardware. We found six of the 17 VMs on our test server were created with version 1.x virtual hardware. Upgrading the virtual hardware is simple enough, but required the VMware utility software in those VMs to be upgraded to the latest version.

Upgrading

Firms already running ESX Server 2.x will probably have heard on the grapevine that the upgrade to VI3 is quite a tricky one, so we looked at this scenario to see what problems are likely to arise. The most risky upgrade scenario is always going to be the in-place upgrade, were a single server is upgraded from one version to another. This route cannot be taken without some server downtime, and as our ESX 2.5.3 system was running two production applications, we needed to perform an in-place upgrade over a weekend. Clearly, the alternative of installing the new software on a new server system enables the old server to keep running until the new one has been successfully installed and the VMs migrated to the new platform, thus avoiding much downtime and risk.