Part of IBM's jump into live migration can be attributed to its acquisition of Meiosys in 2005, a start-up which had captured application live migration capabilities in its software. In some cases, IBM now allows start-ups like Meiosys to pioneer and prove technologies that it used to develop in its own labs.
In addition to moving running applications around, IBM can move a logical partition -- its version of an independent virtual machine -- around as well. Such a unit represents a combination of an application and operating system, plus the memory, storage and networking parameters with which it needs to run. Either the application by itself or the entire logical partition may be moved from one physical machine to another without disrupting end users.
The capability puts a new management tool into the hands of data center operations. Instead of taking systems down at 2 a.m. on Sunday, they can be idled for maintenance and upgrade "at 2 p.m. on Tuesday," or any other time during the regular work week, said Handy. As the work day winds down and workloads diminish, applications running on ten servers might be shifted to one to save power and cooling, he added.