There’s a new problem a few customers have reported whereby-
- ESX disconnects randomly from VirtualCenter
- ESX disconnects when performing VI Client tasks from VirtualCenter.
- Tasks randomly timeout after a long idle time
- “An error occurred communicating to the remote host” pops up.
This only refers to Update 3. This issue seem to be affecting customers with firewalls using state-ful inspection, such as a Juniper ISG 2000, Software Revision 6.1.0R3.
The problem occurs because of SOAP timeouts, and this behavior did not exist in VC 2.0.x or 2.5 GA, as they used a different mechanism to communicate with ESX.
A knowledgebase article is in the works, but Engineering is still actively investigating this problem. One work-around that I have seen mentioned (not verified to work!) is as follows:
- Create a dummy VM on each host (e.g. 16 MB RAM, no disk, no network).
- Set CPU affinity to the last core to prevent VMotion.
- Create a new Scheduled Task that performs:
- Change power state: Power-on dummy VM. Every hour, on the hour.
- Create another Scheduled Task that performs:
- Change power state: Power-off dummy VM. Every hour, 30 minutes after the hour.
Like I said, Engineering is aware of this issue and actively investigating it.