On twitter Mike Laverick asked a question around DRS Affinity Rules and if HA would respect these. In this particular instance the question was around VM-Host affinity rules and I noticed multiple tweeps responding and figured it would not hut to repeat this. There are two different types of VM-Host affinity rules: Must aka mandatory Should aka preferential The difference [...]

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 don’t think anyone has blogged about App Monitoring yet so I figured I would do a “what’s new / intro” to App Monitoring in vSphere 5.0. Prior to vSphere 5 App Monitoring could only be leveraged by partners which had access to the SDK/APIs. A handful of partners leveraged those of which probably Symantec’s ApplicationHA is the best example. [...]

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 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 [...]

We need your help for our VMworld session “VSP1682 – vSphere Clustering Q&A”. In order to ensure we can fill up the full 60 minutes we want to have a couple of questions ready in case no one in the audience has a question. Although I doubt that will be the case, it is better to be prepared than to [...]

When doing some research for the vSphere Clustering Technical Deepdive book I stumbled across something which was very surprising and difficult to grasp at first. I figured explaining it in a short article was the best approach. Many of  you have read the HA deepdive article or the book and know that das.failuredetectiontime is probably the most commonly used advanced [...]