VMware vSphere 4.1 Features Large Capacity Cluster, VM Density

Review: VMware vSphere 4.1's memory compression, storage and network I/O control, along with a cluster limit increase, make the latest virtual machine platform suited for enterprise production use.

VMware vSphere 4.1 continues to lead the enterprise virtual machine platform pack. New memory management, storage and network control features enable resource pool creation that improves scale while reducing performance drags.

Virtual machine management gains increased in importance in the vSphere 4.1 platform, and data center managers should plan on assigning virtualization experts to ensure that the new features lead to improved host utilization and automated scale-out of VM systems.

For a quick look at vSphere 4.1, click here.

During eWEEK Labs tests I learned that vCenter 4.1-the command and control module of VMware's virtual infrastructure world-is now 64-bit only. IT managers should build in extra planning and migration time to move any vCenter 4.0 or older servers to systems that are running a 64-bit OS as part of the move to vSphere 4.1.

The payoff for the vCenter transition is a substantial increase in the number of VMs per cluster and the number of physical hosts that each vCenter can handle. I was not able to test the posted limits due to hardware constraints. VMware states that the latest version of vCenter can handle 3,000 VMs in a cluster and up to 1,000 hosts per vCenter server. Both of these large numbers are a threefold increase over the stated capacity of VMware vSphere 4.0.

Aside from the sizable scale increase enabled by this version of vSphere 4.1, the main advances in the platform are evolutionary extensions of capabilities that improve how the platform handles VM resource contention. During tests, I used the new I/O controls in networking and storage to govern resource use.

IT managers who are already accustomed to using resource controls in VM CPU settings will have a leg up when it comes to using I/O controls in both network and storage areas. Even with the CPU control heritage, my use of network and storage control features revealed a fair number of "Version 1" limitations.