eG Monitoring
 

Measures reported by MemoryDetailsTest

This test reports statistics pertaining to the memory utilization of target systems. The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Free_sys_page_table The number of page table entries not currently in use by the system Number The maximum number of System PTEs that a server can have is set when the server boots. In heavily-used servers, you can run out of system PTEs. You can use the registry to increase the number of system PTEs, but that encroaches into the paged pool area, and you could run out of paged pool memory. Running out of either one is bad, and the goal should be to tune your server so that you run out of both at the exact same time. Typically, the value of this metric should be above 3000. This measure will not be available for non-Windows platforms.
Page_read_rate The average number of times per second the disk was read to resolve hard fault paging Reads/Sec This measure will not be available for non-Windows platforms.
Page_write_rate The average number of times per second the pages are written to disk to free up the physical memory Writes/Sec This measure will not be available for non-Windows platforms.
Page_input_rate The number of times per second that a process needed to access a piece of memory that was not in its working set, meaning that the system had to retrieve it from the page file Pages/Sec  
Page_output_rate The number of times per second the system decided to trim a process's working set by writing some memory to disk in order to free up physical memory for another process Pages/Sec This value is a critical measure of the memory utilization on a server. If this value never increases, then there is sufficient memory in the system. Instantaneous spikes of this value are acceptable, but if the value itself starts to rise over time or with load, it implies that there is a memory shortage on the server.
Pool_nonpaged_data The total size of the kernel memory nonpaged pool MB The kernel memory nonpage pool is an area of system memory (that is, physical memory used by the operating system) for kernel objects that cannot be written to disk, but must remain in physical memory as long as the objects are allocated. Typically, there should be no more than 100 MB of non-paged pool memory being used. This measure will not be available for non-Windows platforms.
Pool_paged_data The total size of the Paged Pool MB If the Paged Pool starts to run out of space (when it's 80% full by default), the system will automatically take some memory away from the System File Cache and give it to the Paged Pool. This makes the System File Cache smaller. However, the system file cache is critical, and so it will never reach zero. Hence, a significant increase in the paged pool size is a problem.This metric is a useful indicator of memory leaks in a system. A memory leak occurs when the system allocates more memory to a process than the process gives back to the pool. Any time of process can cause a memory leak. If the amount of paged pool data keeps increasing even though the workload on the server remains constant, it is an indicator of a memory leak. This measure will not be available for non-Windows platforms.
Commited_bytes_in_use The committed bytes as a percentage of the Commit Limit. Percent Whenever this measure exceeds 80-90%, application requests to allocate memory in the virtual memory (page file). This ratio can be reduced by increasing the Physical memory or the Page file.
Pool_nonpaged_failures The number of times allocations have failed from non paged pool Number Generally, a non-zero value indicates a shortage of physical memory.
Pool_paged_failures The number of times allocations have failed from paged pool Number A non-zero value indicates a shortage of physical memory.
Copy_read_hits The percentage of copy read calls satisfied by reads from the Cache out of all read calls Percent Any value over 80% is excellent.
Copy_reads_sec Indicates the rate at which read operations from pages of the file system cache involve a copy read. Reads/Sec A copy read is a file read operation that is satisfied by a memory copy from a page in the cache to the application's buffer. The LAN redirector uses this method for retrieving information from the cache, as does the LAN server for small transfers. This method is also used by the disk file systems.