This article explains why you might not be able to retrieve Performance Counters and a how to troubleshoot this.
After scanning an Exchange CAS server, the primary LED shows a dark green status. The tooltip for a CAS only server shows "n" performance counters out of "n" cannot be retrieved.
Symptoms
- In the Main View, the tooltip for the server shows: "2 performance counters out of 15 cannot be retrieved".
- The performance counters information from the GSX Monitor server statistics view show: "Download Tasks Completed not found" / "Download Task Queued not found" errors with a "n/a" value.
How it Works
GSX Monitor is collecting Exchange system information that are tied to Exchange configurations. The download task counters are linked to Offline Address Book (OAB) configurations. Under specific circumstances these counters are not available, for example, this behavior can be observed when the CAS server is not participating in an OAB distribution.
You can check your OAB configuration from the Exchange Management Console in Organization Management / Mailbox, under Default Offline Address Book:
The distribution Points are configured in the Distribution tab:
If the CAS server is not in the Distribution Point list, the performance counters will not be created / maintained by Exchange. The counters will only become available when the CAS server is participating in OAB distribution.
This dark green status is for information purpose only, it does not generate any alert or down time in your Exchange availability reports. In fact, this behaviour is expected in some disaster recovery configurations, so GSX Monitor does not rely on these counters to determine server or service availability.