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SQL server 2005 on windows 2003 server with 16GB of RAM /3GB switch cauasing problems

With very large SQL 2000 installs, I always put the following switches in the boot.ini file:


I have just brought up a new SQL 2005 instance on a Windows 2003 server with 16GB of RAM. I added the /PAE, rebooted, and everything worked fine.

Once I added the /3GB switch, I started getting wierd errors like: "cannot connect to SQL server, not enough system resources". So I removed the /3GB switch and now things seem to work fine.

Is /3GB still needed to allow SQL server 2005 to allocate more than 3GB of RAM to the instance? What has changed that I am not aware of?

thanks all!
Microsoft SQL Server 2005Windows Server 2003

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8/22/2022 - Mon

IS AWE enabled on the server?

If yes, have the max server memory in SQL Server configuration properties been restricted to say about 14GB?? If not, restrict the maximum memory available to SQL Server to around 14GB..

It looks like SQL is grabbing all the memory with memory available to OS and other applications being depleted
Jon Winterburn

This is the advice I followed when I needed our SQL Server 2005 server to run 8GB:

Set AWE to enabled.
Run SQL Server under a Windows account that has Lock Pages in Memory enabled.
The Maximize data throughput for network application option of Network Connection in Control Panel must be selected.
Add the /PAE switch to the boot.ini OR the /3GB switch (not both).  Test both to see which works better.  The /PAE switch is generally considered better.

Taken from: http://www.sqlservercentral.com/Forums/Topic412378-146-1.aspx

The /3GB switch needs to be removed only if addressing more than 16GB memory, otherwise it is recommended that it be included in the boot.ini.. This enables SQL Server to take up 3GB of the 4GB base memory and will aid performance..

The /PAE is required to address memory beyond 4GB, so you need both /3GB and /PAE
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OK, I configured AWE, then re-added the /3GB switch and rebooted node1. On reboot I had the same issues: cluster service did not start, I could not log in through terminal service, node1 could not talk to the domain.

I removed the /3GB from the boot.ini and rebooted and everything worked fine.

I am truly stumped on this one.....

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