- Delegated management
- high availability features
- shared file system
- live migration of virtual machines for load balancing and maintenance
- virtual SMP support
- Can't be hosted on non-Intel/AMD processors
- VirtualCenter management is Windows only
- expensive for small deployments
The undisputed heavyweight of the server virtualisation world, the recently updated and re-packaged VMware Infrastructure 3 (VI3) solution is aimed squarely at enterprises looking to consolidate full-scale production systems. As such it’s easily the most scalable of the VMware platforms with additional management, load balancing and high availability features, all designed to take full advantage of the underlying virtualisation technology.
Design & features
In terms of that technology it’s important to understand that VI3 differs from other VMware products -- and, indeed, most other virtualisation platforms -- in that it isn’t dependent on a host operating system. It can still be used to host virtual machines running Windows, Linux and other common operating systems; however it is, itself, based on VMware’s ESX Server, a hypervisor platform installed from scratch onto bare-metal hardware.
There are other differences with VI3, too: for example, it's arguably the most scalable server virtualisation platform around, with facilities to build and run up to 128 concurrent virtual machines on multiple ESX servers, all managed from a central console. Moreover, those servers (virtual and real) can all be configured to share a common file system - the VMware Virtual Machine File System (VMFS), hosted on local disks, NAS or SAN storage (either fibre channel or iSCSI).
VMFS simplifies the provisioning and management of virtual machines. It also makes it possible to dynamically allocate resources and balance processing loads across not just virtual machines, but physical servers too. Indeed, you can even move whole virtual machines from one server to another, complete with active users and applications, with hardly any impact on performance.
Of course, features such as these make VI3 a lot more complicated than other VMware products. Even so, it’s not that hard to get to grips with. Neither is it dependent on exotic hardware: ESX Server is designed to run on industry-standard 32-bit and 64-bit Intel/AMD processors.
Support for Intel's VT technology, as provided on the latest Xeon chips, has also been added in this release along with the AMD equivalent, AMD-V, introduced on Revision F Opteron processors. However, unlike some virtualisation products, there’s no dependence on these processor extensions; you can also mix and match servers together regardless of their processor makeup.
Setup & ease of use
Installation of the ESX software is simplified in VI3 by a Windows-like, install routine. Because the device drivers are all written by VMware, you’re unlikely to encounter compatibility issues; in any case, VI3 is mainly used to virtualise production systems, which inevitably means branded server hardware from the top vendors, all of which are certified by VMware for ESX compatibility.
Another plus is that once installed, the ESX Servers themselves can be more or less left alone, with all of the subsequent management done remotely rather than from a local console. In fact, you don’t need any local server consoles at all.
You do, though, need a separate Windows server (which can be a virtual server if preferred) to host VirtualCenter, the management software used to administer and monitor virtual machines. You’ll also need a Windows desktop from which to run the Virtual Infrastructure client used to connect to it.
The Virtual Infrastructure client provides the interface through which you create, manage and monitor virtual machines. We found this process remarkably straightforward, with tools to both define new VMs from scratch and turn existing instances -- such as working file and print servers, Web servers and so on -- into templates that can then be used to automate the provisioning of others.
Facilities to define resource pools and delegate management of virtual machines within those pools are another time saver. We were very impressed by the VMware Distributed Resource Scheduler (DRS) which can be used to automatically fine-tune processor, memory and other resource allocations. This can also be done manually, but DRS does it better, with no need for intervention as server loads change.
VMware High Availability (HA) is another worthwhile option, adding automatic failover in the event of a hardware or software problem, while VMotion adds the ability to migrate live virtual machines from one server to another for both maintenance and load balancing -- a mind-boggling option that has to be seen working to be believed.
Indeed it’s these extras, building on the underlying virtualisation technology, that put the final icing on the cake. The latest of which is VMware Consolidated Backup, enabling virtual machines to be backed up via automated snapshots to a Windows server rather than having to run backup software on the hosts themselves.
Unfortunately, unlike some other VMware products, VI3 isn’t free -- after all, the company has to make money somewhere. But it is competitively priced, and in this latest format is available in three bundles, each licensed per two physical processor sockets.
The cheapest of the bundles is the $1,000 (~£528) Starter edition aimed at smaller businesses and distributed branch office networks. This comes with VirtualCenter management and the ESX Server software, but is limited to four physical processors and 8GB of memory per server. Support for fibre channel and iSCSI storage is also omitted in this version, but you do get the Virtual Machine File System, which can be used with local storage and NAS servers.
Higher up the scale, the $3,750 (~£1,979) Standard edition is the starting point for most datacentre deployments. This edition lifts the processor and memory restrictions, also adding support for SAN storage and 4-way virtual SMP per VM.
Finally, there’s the all singing, all dancing, $5,750 (~£3,035) Enterprise edition, which comes with everything including live virtual machine migration using VMotion, the Distributed Resource Scheduling component and both the High Availability and Consolidated Backup options.
Each of these options is also available separately, along with installation and support services, from VMware and its partners. You can even download a 30-day evaluation copy and find out for just what VMware Infrastructure 3 can do for you.