February 27, 2013 at 12:47 am
From SQL Server error log, i found following information:
[highlight=#ffff11]2009-06-04 12:21:08.16 Server Large Page Extensions enabled.
2009-06-04 12:21:08.16 Server Large Page Granularity: 2097152
2009-06-04 12:21:08.21 Server Large Page Allocated: 32MB [/highlight]
It seems my SQL Server enabels large pages. As my database is OLTP and enable large pages may hurt performance, so i want to turn it off.
My SQL Server is 2005 Enterprise(64 bit) and has 12GB RAM. Service account is local system, trace flag 834 is turned off.
Is there a way to make SQL Server not enable large pages? Currently i don't want to change my service account.
Thanks in advance?
February 27, 2013 at 12:59 am
It's not using large pages, don't worry about that. Without traceflag 834 SQL won't use large pages, it enables the extensions, but that's all.
http://blogs.msdn.com/b/psssql/archive/2009/06/05/sql-server-and-large-pages-explained.aspx <- explained there why you see that entry in the error log.
When SQL's actually using large pages, your error log entry looks like:
2009-06-04 14:20:31.13 Server Large Page Extensions enabled.
2009-06-04 14:20:31.13 Server Large Page Granularity: 2097152
2009-06-04 14:20:31.14 Server Large Page Allocated: 32MB
2009-06-04 14:20:40.03 Server Using large pages for buffer pool.
2009-06-04 14:27:56.98 Server 2048 MB of large page memory allocated.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
February 27, 2013 at 1:07 am
Thanks Gail. When i query memory utilization by SQL Server, i found AWE allocated about 2GB, working set only taken 88MB ,is it normal?
Query AWE allocated memory:
select
sum(awe_allocated_kb) / 1024 as [AWE allocated, Mb]
from
sys.dm_os_memory_clerks
February 27, 2013 at 1:12 am
How are you seeing the working set? Let me guess, task manager?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
February 27, 2013 at 1:12 am
yes, from task manager.
February 27, 2013 at 1:21 am
Never use task manager to check SQL's memory as it will display incorrect values if you have locked pages enabled (Task manager limitation)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
February 27, 2013 at 1:23 am
got it. thanks so much.
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