I was facing this issue for the last two days ago, one of my customer complained one of their exchange mailbox server performance slow and the CPU utilization is 100%. Our customer is using VMware and all the VMs server running on top of the VMware.
When checking on the server that has performance issue, I found out all the services running as usual, the fail-over cluster up and running, but the connectivity to this server seems very slow. When open the EMC we got this error below;
Processing data for a remote command failed with the following error message: The WinRM client cannot complete the operation within the time specified. Check if the machine name is valid and is reachable over the network and firewall exception for Windows Remote Management service is enabled. For more information, see the about_Remote_Troubleshooting Help topic.
After deeply checking with the VMware team, we found out that both
exchange mailbox servers require to perform Disk Consolidation. It is
because their backup for VMware has a problem and too many "VM snapshot"
created for these two servers and its impact to server performance. After the VMware team finished performing the disk consolidation, the issue has resolved and the mailbox server back to normal.
