Our Exchange 2013 server is very slow. The cpu is running at 80-90% with 90% memory utilization all day . The server is running as a virtual machine in on an ESXi host server with 8 cpu's and 8GB of memory assigned. There are only about 50 users with a db less than 100 gb. Looking at the running processes I see several instances of noderunner running in the background and consuming over 50%. any idea what the noderunner process is doing and why there is multiple instances?