With the launch of its free VMware Server product last year, EMC subsidiary VMware was clearly looking to tempt cost-conscious small businesses into its server virtualisation fold. However, the one thing the product lacked was a centralised management console, requiring each host server to be administered separately. Until now, with the release of a new version of VMware’s VirtualCenter application, designed specifically to manage the free server product.
The new VirtualCenter is in fact an update to the tool used to manage VMware GSX and ESX Server deployments, with support for VMware Server added along with a number of other minor tweaks. However, it’s important to understand that there’s still no support for VMware Server in the more advanced Virtual Server 2.0 application included in the vendor’s enterprise platform, Virtual Infrastructure 3 (VI3).
For a product aimed at small business we found VirtualCenter for VMware Server quite complicated and longwinded to install. Plenty of time spent reading the manual is essential, in addition to which a number of pre-requisites need to be borne in mind. In particular the need for a Windows host with a fast processor and at least 2GB of RAM for the main VirtualCenter Server component (an SMP server and additional memory is recommended for more that 50 servers). This, however, can be a virtual machine, and can also be used to support an optional shared data store where virtual machine files can be located.
A database is also required to store host and VM settings. A simple Access database can be used for testing and evaluation but, for optimum performance, an SQL Server or Oracle database is recommended.
A separate Windows-based VirtualCenter Client looks after the GUI. This can be installed and run on the same Windows machine as the server but will, more typically, be hosted on a remote desktop PC. The Microsoft .Net framework is required to support it, and will be installed automatically if not already in place.
No changes are required to the VMware Server deployments, as the necessary VirtualCenter agent will be added when a server is discovered. However, it’s a good idea to upgrade to the latest versions as part of the deployment process. VirtualCenter also requires licences for each of the hosts to be managed - a relatively straightforward task which, for some reason, VMware makes quite complex.
It all takes time to get right, but once up and running we were quickly able to logon to the VirtualCenter server and start managing the VMware Servers on our test network. The Client employs a familiar hierarchical tree interface, with VMware hosts organised into farms while virtual machines are grouped and managed independently.
We started by creating a new server farm to which we added a couple of host VMware Servers, one running on Windows Server 2003, the other on Red Hat Linux. A wizard is helped take us through the discovery process with existing virtual machines automatically added to the list of resources. After which we were able to create new virtual machines, start and stop them, tinker with their setup and connect via an integrated remote console, all from the VirtualCenter client.
Other tools are provided to clone virtual machines, and create templates for rapid deployment of new VMs. Plus there’s a wizard to migrate virtual machines from one server to another, for example, to balance loads or free up a server for maintenance. However, VMs have to be stopped before they can be migrated with no live migration facilities like those found in VI3. Similarly there are no facilities to allocate processor and other resources or dynamically balance loads as in VI3, principally because VMware Server doesn’t allow it.
Indeed it’s worth pointing out that, apart from centralised management, VirtualCenter adds very little in the way of extra functionality on top of what comes as standard in VMware Server itself. The only exception is the ability to monitor virtual machine activity and set alarms when, for example, a VM hangs or CPU/memory usage exceeds pre-set limits. There are also tasks you can’t perform from the VirtualCenter, such as take VM snapshots, which mean you can’t throw away the individual server console altogether.
Given its limitations and cost, VirtualCenter for VMware Server is far from an obvious purchase. Its main advantage is clearly the convenience of being able to manage a distributed virtual infrastructure from a single console, but you do need a critical mass of servers to make that worth having.
VMware itself reckons that the product will appeal to companies with 10 or more physical servers and we agree. Especially as there’s little you can do with VirtualCenter that can’t be done using the free tools supplied with VMware Server itself. If you only have a handful of servers you might as well save the not inconsiderable amount of money required and look after each one individually.
Small businesses will should think carefully before buying VirtualCenter for VMware Server. Its principal benefit is the centralised management of multiple servers and their VMs, but it’s far from cheap and requires additional server resources adding further to the cost. As such it can only be justified for larger deployments where the productivity benefits of a central management console make it worth considering.