For one of my servers with below configuration:
Total RAM: 32 GB
CPU: 8
Max Server Mem: 22.5 GB
Min Server:: 4 GB
Edition: Enterprise Edition with 2k8R2 installed on SP3
Page file: System Managed on the C:\
AWE Enabled: NO as it being 64 Bit
I am continuously getting the alerts for OS paging High..
When I checked using RAMMAP Tool for memory utilization, I found that there is AWE which using an approx of 23.8 GB and thus blocking any further memory usage:
More over for the user right assignments : "Locked pages in Memory" has not been assigned any rights!
Kindly help me understanding where more I need to investigate, or a solution for this
Thanks!
Best Answer
Memory is basically two types the physical random access memory (RAM) and virtual memory. A process has to be first mapped to Virtual memory and then to physical memory. All programs use RAM, but when there isn't enough RAM for the program you're trying to run, Windows temporarily moves information that would normally be stored in RAM to a file on your hard disk called a paging file. The amount of information temporarily stored in a paging file is also referred to as virtual memory. Now error page file is less can have multiple meanings
You are running some processes which is heavily utilizing memory and since OS cannot find enough RAM for it it has to use Page file as temporary area for storage.
Since SQL Server is running with Locked pages in memory privilege this memory cannot be paged out to disk and OS cannot directly used this memory by asking SQL Server to release it heavily. So in this case you need to lower max server memory of SQL Server a bit and give more memory to OS so that it can function properly. use how to set optimum value for max server memory to set correct value for max server memory. In your case you have left 10 G for OS which I consider is pretty much good unless you are using SSIS,SSAS and SSRS.
Problem may be not SQL Server memory or memory allocated by AWE API( Locked pages) problem here is windows page file size is less. You need to act on this. Page file is temporary area which is used to hold temporary data which is swapped in and out of physical memory in order to provide a larger virtual memory set. Page file space is reserved when the pages are initially committed, however the page file locations are not chosen until the page is written to disk.
The page file needs of an individual system will vary based on the role of the server, load etc. There are some performance counters that you can use to monitor private committed memory usage on a systemwide or per-page-file basis. There is no way to determine how much of a process' private committed memory is resident and how much is paged out to paging files.
Memory: Committed Bytes: Number of bytes of virtual memory that has been committed. This does not necessarily represent page file usage - it represents the amount of page file space that would be used if the process was completely made nonresident
Memory: Commit Limit: Number of bytes of virtual memory that can be committed without having to extend the paging files.
Paging File: % Usage Percentage of the paging file committed
Paging File: % Usage Peak Highest percentage of the paging file committed
Please use above counters to set proper value for page file. You can read This Link to get more information about page file
You can set page file by Right click on My Computer select properties and then go on Advanced System Settings.In Performance section click on setting and then advanced tab. You would see virtual memory section and then click on change you can set virtual memory here. Please refer to screenshot. Take help of windows team in configuring optimum value. If option automatically set page file for drives is set you can uncheck it and click on SET to set optimum value of page file.
This is pretty much normal considering the fact that SQL Server service account is Local system so by default SQL server account will get Locked pages in memory privilege.