I received a question today about a partitioned clusters (in vSphere 5.0) with HA. The question was which Master would own which VMs when a partition exists and how is determined which master can own which VM? I have already briefly explained the difference between an isolation and a partition. Now it is good to realize that when a partition [...]

I just read Eric’s article about all the topics he covered around vSphere 5 over the last couple of weeks and as I just published the last article I had prepared I figured it would make sense to post something similar. (Great job by  the way Eric, I always enjoy reading your articles and watching your videos!) Although I did [...]

I received a question last week about higher latency thresholds for vMotion… A rumor was floating around that vMotion would support RTT latency up to 10 miliseconds instead of 5. (RTT=Round Trip Time) Well this is partially true. With vSphere 5.0 Enterprise Plus this is true. With any of the versions below Enterprise Plus the supported limit is 5 miliseconds [...]

I just wanted to point out a couple of changes for HA in vSphere 5.0 with regards to admission control. Although they might seem minor they are important to keep in mind when redesigning your environment. Lets just discuss each of the admission control policies and list the changes underneath. Host failures cluster tolerates Still uses the slot algorithm. Major [...]

**disclaimer: Some of the content has been taken from the vSphere 5 Clustering Technical Deepdive book** The first time I was playing around with 5.0 and particularly HA I noticed a new section in the UI called Datastore Heartbeating. Those familiar with HA prior to vSphere 5.0 probably know that virtual machine restarts were always initiated, even if only the [...]

**disclaimer: Some of the content has been taken from the vSphere 5 Clustering Technical Deepdive book** As mentioned in an earlier post vSphere High Availability has been completely overhauled… This means some of the historical constraints have been lifted and that means you can / should / might need to change your design or implementation. What I want to discuss [...]

** Update: Available now: paperback full |paperback black & white ** After months of hard work the moment is finally there, the release of our new book: vSphere 5.0 Clustering Technical Deepdive! When we started working, or better said, planning an update of the book we never realized the amount of work required. Be aware that this is not a [...]