Upgrading to VMware Tools 5.1 can cause log spew
It’s not everyday you get a KB article with LOG SPEW in it’s title …
This particular one was spotted by Aaron Silber after upgrading VMware Tools on a XenApp Server and subsequently researching the noted RPC errors. If you look at the event log below, you will notice a warning event every SECOND or so in the Application log. SPEW seems to be a pretty good classification for that type of behavior.
The quick fix is to disable logging on the Virtual Machine but the better long term fix is to upgrade your ESXi servers to 5.1 Update 1. I think it is also interesting to note that you can trigger the change for logging by changing the settings for the Virtual Machine and then rebooting the VM (expected), but also by just vMotioning it to another host (unexpected).
You can check out the KB article here: http://kb.vmware.com/kb/2036350?src=vmw_so_vex_ccost_793