Post reply

AWE Memory

  • March 16, 2004 at 9:06 am

    #107852

    Hi All,

    I just configured and deployed a new DB server.  We have three DB's running on it - approx size 45GB.  The DB server has 6GB of memory on it and so when installing, I decided to use AWE (Advanced Windowing Extensions).    I alloated 5GB to SQL Server and left the rest for the OS.  Nothing else is running on that server besides SQL.  Now when I look at the memory used by SQL server through task manager, I see 5GB alloted to it but it uses anywhere from 350MB to 400MB of memory only.  Looking at my standby DB, which is not configured to use AWE memory and is set to dynamic, I see SQL Server using 1.8GB of memory.  So I am not convinced that AWE is the best solution in my case.  Can someone shed some light on this.

  • March 17, 2004 at 8:09 am

    #499120

    When you are using AWE you will not see much memory usage by sqlserver in Task Manager.  Your Commit Charge (Total) should show the memory as being used.

     

  • March 17, 2004 at 8:44 am

    #499132

    That's right ... also Task Manager does not know how to properly display memory that is mapped via AWE (and/or the Programmable Address Extensions).

    Perfmon or Pstat can can give you some addtional insight into the AWE Memory areas.

  • March 17, 2004 at 9:35 am

    #499151

    I agree with last answer, BTW did you check your boot.ini file to enable the extra memory to Windows /PAE?

  • March 17, 2004 at 10:46 am

    #499166

    thanks guys,  Yes made the changes to the Boot.ini.

  • March 18, 2004 at 9:23 am

    #499350

    You may want to try putting the /3GB in your boot.ini as well.  If you don't, windows reserves 2GB of memory for Kernal use and 2GB for User Space.  Using the 3GB will give you 3GB of User Space.

    A couple warnings, you only can use /3GB if you have <=16GB of memory and there is an issue with this and Multiple SCSI controllers.  Check MS Knowledge Base Article:819636

     

  • March 19, 2004 at 11:30 am

    #499556

    A while back, Compaq Support recommended the following to us for monitoring AWE memory:

    select cntr_value, cntr_type from sysperfinfo

          where

                object_name = 'SQLServer:Memory Manager' and

                counter_name = 'Total Server Memory (KB)'

    Watch the following "SQLServer:Buffer Manager" counters in Performance Monitor:

    AWE lookup maps/sec

    AWE stolen maps/sec

    AWE unmap calls/sec

    AWE unmap pages/sec

    AWE write maps/sec

    Buffer cache hit ratio

    Hope this helps,

    Jon

Viewing 7 posts - 1 through 6 (of 6 total)

You must be logged in to reply to this topic. Login to reply