16 July,2012 by Jack Vamvas
Question: A server hosting a SQL Server is experiencing higher than normal levels of the Performance counter: Memory:pages/sec than normal? Does this mean memory pressure is occurring?
Answer: Yes and No . The Memory:Pages\sec counter is a good indicator of memory pressure and subsequent paging. However, the Memory:pages\sec counter includes other activity, such as reading memory mapped files (MMF)
For memory pressure read : SQL Server Performance ,memory pressure and memory usage
1) Definition of Memory: Pages/sec “The Memory:Pages/sec counter reports the number of pages that are retrieved from disk needing to resolve memory references to pages that weren’t in memory at the time of reference”
2) Pages/sec = Pages Input/sec + Pages Output/sec.
3) The counter includes sequential reading of MMF. MMFs assist applications to access files on disk the same way they access active memory. The application maps its virtual address space directly to disk (file). High Number of Memory:Available Bytes & normal Paging File: % Usage is a good indicator for this activity.
4) The Memory:pages\sec counter on its own gives a partial picture. When creating a baseline or troubleshooting , I prefer to use a wider range of counters. If the problem is SQL Server related , aim to isolate the SQL Server activity'