Latest version of ESX 3.5 update 2 had been impressed with the advance monitoring which will ensure if you had your VM hang up from the Operating System perspective, it will force the VM to be restarted due to the heartbeat connection is lost. This has been some good features and effort from VMware I will said.

At the same time, I will say this is not fit to my environment. Maybe you guys had experienced the similiar situation with the patches release from ESX always Require VMtools to be upgraded. I am still concerning why it require VMtools to be upgraded for any minor or major update from the ESX release. This actually had caused us a lot of time to negotiate with the down time to ensure the VM are patch with the latest version of VMtools. Again, when the VMtools is not updated, the heartbeat will be inconsistent of not detected.

In this case, you will not able to enable the sweet monitoring features been released recently. Therefore, I am currently urge the VMware, trying to reduce the number of time require to upgrade the VMtools. We can patch the ESX with no down time. But, if you need to upgrade VMtools, that will be down time required.

Something VMWare has to be seriously look at about their software development cycle with the tools they release.