August 24, 2010, 8:08 PM — VMware's vSphere 4.0 cloud operating system, which we tested last June ushered in new methods to manage virtual machines on internal and external hosts. The 4.1 version, which shipped last month, delivers some much needed polish. Additions to the product include an updated vCenter Configuration Manager (formerly EMC's Ionix Application Stack Manager and Server Configuration Manager) as well as vCenter Application Discovery Manager (formerly EMC's Ionix Application Discovery Manager).
Prices now range from the free basic hypervisor to Enterprise Plus at $3,495 per processor.
Of the features tested, we found vMotion to have the most immediate effect for administrators, although those trying to cram as many VMs as possible onto a physical server will find newly reduced memory overhead and memory compression options to be highly desirable. After all, virtualization is all about optimization.
VMware 4.1 contains a sorely needed feature, the ability to use vMotion to move more than one VM at a time from server host to server host. VSphere 4.1 allows several VMs to move concurrently, but with a small catch.
The catch is that the source and target machines still need to be similar to each other in terms of processor type, and there needs to be a connection between the machines with reasonable speed — the two Gigabit Ethernet jacks found on most servers will do the job for at least four concurrent VM moves, we found in testing. (See our test methodology.)
With a 10GB switch, enterprise customers can expect to be able to move eight machines at once across a VMware cluster.
These improvements address the issue of how to quickly get production virtual machines off a failing hardware platform. When hardware sends alarms that problems are occurring, maintaining production requires moving the dense number of operating systems instances to another platform rapidly, and eight VMs at a time seems to be a good number.