VMware vSphere 4.1: Review

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 centre managers should plan on assigning virtualisation experts to ensure that the new features lead to improved host utilisation and automated scale-out of VM systems.

Migration

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.

First version limitations

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.

Network I/O control prioritises network traffic by type when using network resource pools and the native VMware vNetwork Distributed Switch. Network I/O control only works with Version 4.1 of the vNetwork Distributed Switch; not Cisco Nexus V1000 and not the standard switch from VMware. IT managers who are already using the vNetwork Distributed Switch will need to upgrade to Version 4.1.