For many IT practitioners undertaking virtualization and weighing various product offerings, the question is this: Why purchase VMware Infrastructure Suite rather than simply VMware ESX?
There's no doubt that VMware ESX provides an excellent platform for server consolidation through virtualization. With its ability to place multiple-guest virtual machines on a single physical server, ESX can save a company thousands of dollars.
But that's not to say there aren't clear advantages to VMware Infrastructure Suite.
VirtualCenter is the backbone of the suite, and is required for most of the additional tools. VirtualCenter is the front-end management component of the virtual infrastructure, allowing an administrator to configure a single guest operating system, single ESX host, a cluster of ESX hosts, a complete data center of ESX hosts, or multiple datacenters of ESX hosts. VirtualCenter is where an administrator can configure guest operating system resource reservations (ensuring a minimum amount of CPU, memory, and I/O resources), resource limits (so a single guest can not consume all of the resources of a host), performance monitoring and reporting, and other advanced components.
VMware High Availability
VMware High Availability (HA) is an add-on component to VirtualCenter that will reboot a guest operating system (cold migration) to either the same host (in the case of a guest operating system crash) or another host (if there is an ESX Server crash or limited resources on the original host). This functionality also provides administrators with the option of configuring scripts to run when ESX detects that a server has crashed or has "locked up" and performing an automated reboot, minimizing downtime.
VMotion builds on the concepts of HA by allowing an administrator to migrate a guest operating system from one ESX host to another, while the guest system is still running (warm or live migration). The memory map of the guest operating system is transferred to the new host, while the new host reads the guest configuration files from a shared storage infrastructure (SAN/NAS). DRS expands this functionality by dynamically balancing workloads across a cluster of ESX hosts by analyzing resources on each ESX host, and either providing an administrator recommendations for migrating a guest operating system to a new host or automatically executing a VMotion of the guest operating system to the new host. This allows the guest operating system to continue in normal operations while saving state and maximizing the amount of hardware resources available to the guest, significantly decreasing hardware-related downtime for your application environment.
Overall, VMware ESX and the Virtual Infrastructure tools provide an administrator a host of products that can improve the availability, flexibility, and utilization of servers in the data center. Based on these improvements, as well as the time savings these tools yield for basic management tasks, if you're looking for an enterprise solution and started with ESX, you'll be well-served to go all the way with the VI3 suite.
Craig A. Newell is a senior consultant at Focus Consulting and works with end users on needs/technology assessments and evaluation/implementation involving virtualization, server consolidation and blade systems.
Barb Goldworm is president and chief analyst of Focus Consulting, a research, analyst and consulting firm focused on systems, software, and storage. She has spent thirty years in various technical, marketing, senior management, and industry analyst positions with IBM, Novell, StorageTek, Enterprise Management Associates, and multiple successful startups.