Last week at VMworld and on the VMTN community I had a couple of questions around resource management and HA Admission Control. It appears people were using HA Admission Control for managing resources within their environment. In other words, the amount of VMs that HA would allow you to restart would be leading for managing resources. But is that what [...]
A couple of weeks ago I was contacted about an issue with vSphere 5.0. When a VM Storage Profile was disabled / enabled it looked like HA and DRS got disabled as well. After diving in to the problem it appeared that both HA and DRS were still working. It seems that some how the vSphere Client thinks it is [...]
I was reading a whitepaper by VKernel and it mentioned the following “a failover host for these VMs requires sufficient idle resources“. In this whitepaper it is discussed how Monster VMs pose challenges for both HA and DRS. As I had a similar question last week at VMworld I figured I would post this. Also because it is fundamental to [...]
Last week I did an article about Datastore Heartbeating and the prevention of the Isolation Response being triggered. Apparently this was an eye-opener for some and I received a whole bunch of follow up questions through twitter and email. I figured it might be good to write-up my recommendations around the Isolation Response. Now I would like to stress that [...]
I had a discussion via email about metro clusters and HA last week and it made me realize that HA’s new architecture (as part of vSphere 5.0) might be confusing to some. I started re-reading the article which I wrote a while back about HA and metro / stretched cluster configurations and most actually still applies. Before you read this [...]
I was just listening to some of the VMworld sessions and one was about HA. The presenter had a section about Datastore Heartbeats and mentioned that Datastore Heartbeats was added to prevent “Isolation Events”. I’ve heard multiple people make this statement over the last couple of months and I want to make it absolutely clear that this is NOT true. [...]
I just finished overhauling the vSphere HA Deepdive page. It now includes details about all versions of HA but is specifically split up in two sections: 4.1 and prior 5.0 I also cleaned up all comments. Although there were a lot of useful details in there the amount of comments made it impossible to maintain. With all changes in 5.0 [...]
