AWE memory
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This saturday, we will be configuring a server to use AWE memory so SQL can use up to 3 GB out of the 4 GB available to it. Later on, we will also be upgrading it to Windows 2000 Advanced Server with 6 or possibly 8 GB of memory, but for now we'll stick with Windows 2000 Server. The server has a couple of not-very-memory-intensive applications running on it, that's why we're leaving 1 GB for the system and these apps.
Now, I think I have read more or less all there is to read about this at MS site and BOL, plus a couple of other places, but I thought I'd check if there was anyone who had some special advice that I should be aware of?
Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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Not much to it. Use /3GB in boot.ini.
Andy
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Windows 2000 Server and SQL 2K Std do not support AWE. You will need Advanced Server or Datacenter and SQL 2K EE. /3GB enables 4GTune, but that is not AWE.
JM
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As far as I've understood, the /3GB switch is not available in Windows 2000 Server?!?
We have Windows 2000 Server and SQL 2000 Enterprise Edition, which should give us the possibility to use AWE. Or am I totally wrong here? As I said, I've never done this, just read the documentation, but of course, experience beats documentation any day.
In this article (http://support.microsoft.com/default.aspx?scid=kb;[LN];Q274750) it specifically says that you can not use /3GB in Windows 2000 Server, but AWE support up to 4 GB memory is available:
quote:
Support for Operating System VersionsWindows 2000 Server
Normally, both the SQL Server 2000 Enterprise Edition and SQL Server 2000 Developer Edition can use up to 2 GB of physical memory. With the use of the AWE enable option, SQL Server can use up to 4 GB of physical memory.
NOTE: You cannot allocate more than 4 GB of physical memory to an application on Windows 2000 Server because Physical Address Extension (PAE) is not available on Microsoft Windows 2000 Server. Also, you cannot use the 3 GB switch in the Boot.ini file with Windows 2000 Server; however, you can use the 3 GB switch in the Boot.ini file with Microsoft Windows 2000 Advanced Server or Microsoft Windows Datacenter versions.
Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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Correct! So, if you ever plan on more than 4 gig in a server you will need to upgrade the OS and SQL 2000 If I am not mistaken. Under Windows NT 4.0 you could only use 2 gig flat and had to upgrade to enterprise to get anything above that and use the /3gb switch.
Wes
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OK, great. We are running SQL 2000 Ent, so I think we're OK there
, but yes, we need to upgrade to Windows 2000 Advanced Server to go further.Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
Edited by - chrhedga on 08/16/2002 01:47:29 AM
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Thought I'd post a quick followup on this. Did the upgrade this saturday and enabled AWE memory usage, without any problems at all. Funny thing though, it seems that sqlservr.exe in Task manager now shows memory usage except for data cache or something, because it doesn't go higher than 70 MB (used to be 1.7 GB). Anyone else seen that?
Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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AWE memory, as distinct from using /3GB, is out of the windows paged area and access is managed from the process itself, rather from the virtual memory manager subsystem. So my guess is that its allocation invisible to the kernel and that why task manager can't see it.
Have you tried asking the server how much memory it thinks it's using?
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Haven't tried it yet (will do tonight), but that's what I thought as well. The total amount of memory used on the server seems to reflect this.
Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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Mine shows 280k memory used with 7.5g allocated to sql.
Andy
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Did anyone ever figure out why Task Manager incorrectly reflects the memory utilization for SQL when AWE is enabled? Curious. Thanks.
David
David
@SQLTentmaker“He is no fool who gives what he cannot keep to gain that which he cannot lose” - Jim Elliot
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quote:
Did anyone ever figure out why Task Manager incorrectly reflects the memory utilization for SQL when AWE is enabled?Yes, clickfund's answer above is more or less correct. Windows itself does not have a clue that SQL Server is using a lot of memory above the 4 GB that the virtual memory manager of the OS is aware of.
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Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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I use the perfmon counter sqlserver:memory manager/total memory(kb) to get a accurate feel of how much SQL is using the available memory in the box.
Wes
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quote:
I use the perfmon counter sqlserver:memory manager/total memory(kb) to get a accurate feel of how much SQL is using the available memory in the box.Yep, since this is what SQL Server itself says, this counter is correct.
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Chris Hedgate @ Apptus Technologies (http://www.apptus.se)
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Thanks. It was my plan as well to use the Perf Mon however having a few problems there. Will get them ironed out as I believe Antares post to http://www.sqlservercentral.com/forum/link.asp?TOPIC_ID=9956 will get it fixed. Thanks for the feedback!
David
David
@SQLTentmaker“He is no fool who gives what he cannot keep to gain that which he cannot lose” - Jim Elliot
, but yes, we need to upgrade to Windows 2000 Advanced Server to go further.Viewing 15 posts - 1 through 14 (of 14 total)
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