System Up Time Alarm

This alarm is activated when the system up time exceeds the value specified in the related threshold.

Total CPU Usage Alarm

Total CPU Usage Alarm

The Windows CPU alarm is activated when the average CPU utilization of the system exceeds a threshold. This value is taken over a specific number of refresh intervals (by default, four).

Sustained high CPU utilization can adversely effect the performance of the system.

When this alarm is current, you should:

• Look at the Processes tab on the Processes drilldown to see which Windows process is consuming the CPU.
• Consider upgrading to a faster CPU or adding processors to your system.
• Look at the Paging Activity page on the Memory drilldown to see if there is a high paging rate. High paging rate can cause inflated CPU utilization. If this is the case, adding more memory to the system may overcome the problem.

Related Topics

Processes Page

Paging Activity Page

Virtual Address Space Alarm

This alarm becomes active when a process approaches the two gigabyte virtual address space limit imposed by Windows. Processes attempting to exceed this limit may fail catastrophically. Any process that approaches this limit should be closed to free the address space and then restarted if required.

Regardless of the amount of physical memory in your system, Windows uses a virtual address space of 4 GB, with 2 GB allocated to user-mode processes (for example, applications) and 2 GB allocated to kernel-mode processes (for example, the operating system and kernel-mode drivers).

NOTE: Some versions of Windows Server allow users to change this ratio to 3 GB for user-mode and 1 GB for kernel-mode processes via the /3GB switch in boot.ini. Versions that support this switch are:

• Windows 2000 Advanced Server
• Windows 2000 Datacenter Server
• Windows Server 2003 Enterprise Edition
• Windows Server 2003 Datacenter Edition.

Windows Server 2003 x64 Editions do not support the /3GB switch. On these systems:

• 32 bit processes compiled with the /LARGEADDRESSAWARE switch can increase their virtual address space limit to 4GB
• 64 bit processes can access up to 8TB of virtual address space.

Thus this alarm is disabled for 64 bit systems.

Virtual Memory Alarm

This alarm is activated when free virtual memory drops below a threshold.

When this alarm is current you should:

• Look at the Processes page on the Processes drilldown. Look at the VM Size (MB) column to see which applications are using the most virtual memory.

  Some applications (such as Microsoft Exchange or Microsoft SQL Server) can have their memory utilization limited.

• Close any superfluous processes.
• Look at increasing the size of the page file.
• Look at increasing the amount of RAM in the machine.

Related Topics

Processes Page