Just doesn't make any sense. Over the weekend we upgraded several hosts from 5.1 to 5.5 U3. Done this (literally) hundreds of times. As soon as they all came online and started hosting VM's, memory red-lined on every host. Balloon, swap in/out, and compression metrics are through the roof.
Now for the really weird part (before everyone starts rolling their eyes).... VMware Tools IS installed on every single VM.
Anyone have any ideas?
SAN latency is fine, as always. Network util is very low, as usual. No other changes to the environment whatsoever.
Please let me know if anyone has any thoughts, or if I missed some overnight critical patch or something.