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Memory usage not matching up with that shown in DMV's Expand / Collapse
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Posted Monday, April 15, 2013 3:23 AM
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I have a sql 2005 64bit instance on a 64bit windows server.
The Server has 32Gb RAM Total with 26GB set as MaxServerMemory for SQL Server.
Lock Pages in Memory is enabled for SQL Server.

We are getting a lot of very Low Page Life Expectancy alerts on this server.
External memory pressure is not the problem so it has to be internal to sql server.

On checking the sys.dm_os_memory_clerks to help identify high consumers in single and multi page allocators, we can only see that about 4Gb is used by single page allocations and 3GB is used by multi page allocations.

We cannot see where the rest of the memory is being used.

Im not sure what next steps to take to identify the heavy consumer of RAM, so any suggestions would be appreciated.

Thanks!
Post #1442214
Posted Monday, April 15, 2013 6:48 PM


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This will sound stupid-simple but have you tried just looking at TaskMgr on the box? It provides a pretty good 60,000 foot view of such things.

--Jeff Moden
"RBAR is pronounced "ree-bar" and is a "Modenism" for "Row-By-Agonizing-Row".

First step towards the paradigm shift of writing Set Based code:
Stop thinking about what you want to do to a row... think, instead, of what you want to do to a column."

(play on words) "Just because you CAN do something in T-SQL, doesn't mean you SHOULDN'T." --22 Aug 2013

Helpful Links:
How to post code problems
How to post performance problems
Post #1442552
Posted Tuesday, April 16, 2013 12:33 AM


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-- Good basic information about memory amounts and state
SELECT total_physical_memory_kb, available_physical_memory_kb,
total_page_file_kb, available_page_file_kb,
system_memory_state_desc
FROM sys.dm_os_sys_memory WITH (NOLOCK) OPTION (RECOMPILE);

-- You want to see "Available physical memory is high"


-- SQL Server Process Address space info
--(shows whether locked pages is enabled, among other things)
SELECT physical_memory_in_use_kb,locked_page_allocations_kb,
page_fault_count, memory_utilization_percentage,
available_commit_limit_kb, process_physical_memory_low,
process_virtual_memory_low
FROM sys.dm_os_process_memory WITH (NOLOCK) OPTION (RECOMPILE);

-- You want to see 0 for process_physical_memory_low
-- You want to see 0 for process_virtual_memory_low

Post #1442612
Posted Tuesday, May 21, 2013 4:45 AM


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Is this on a physical server or a VM?




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Post #1454918
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