As you probably know vSphere 5.0 introduced lots of improvements to VMotion – too many to list here (such as multi-nic support and increasing the number of simultaneous VMotions). The good thing to say is that the engineers behind VMotion continue to enhance and develop what many people still see a flagship feature. It’s interesting to remember that VMotion was like back in the ESX 2.x days when I first saw it. For me it was a WOWMoment. Literally jaw drop-dropping, one of the things (amongst many) that convinced me in 2003/4 that I must get into this new-fangled “virtualization” thang, it would be thing of the future. Up there with your own personal jetpack!
Back then a lot of people were little to hasty in dismissing VMotion as “toy” – like it was some kind of engineering grandstanding. But if you think about without VMotion a lot of other very important features we now take for granted probably would never have been developed such as DRS and Maintenance Mode. For me its bit like when short-sighted people question the esoteric science research as being “faddy” and not relevant to the real world. But it’s from that groundbreaking research that often whole new industries are borne.
VMotion without Shared Storage
Anyway, less of the nostalgia trip and more about what’s new. The big thing is you can now do VMotion without shared storage. It’s actually a kind of management tool in this respect as couple the features of Storage VMotion and VMotion together to allow you to move a VM between clusters. There are some requirements that have to be meet for it to work, but in most case these requirements have been around for some time. So for example the target and source ESX hosts must reside within the same Layer2 network within the same vCenter, Datacenter and (if you are using them) the same Distributed vSwitch. Right now neither DRS or SDRS use this feature and it currently limited to 2 simultaneous moves.
For me this is another example of us breaking through the cluster as a management boundary. It’s not like the cluster is going away, but in the past its been difficult to move workloads between one cluster and another. And I think this chimes well with some of the changes that will be present in vCloud Director 5.1. But more about that later!