AWE Enabled but no gains in Memory Usage by SQL Server- Requesting Help

  • Hi All,

    Server Stats: Physical Server having Win 2003 SP2 server + SS 2005 Standard Edition SP2 (9.00.3042) + 12 GB RAM + /PAE already set

    Want to increase the usage of RAM by SQL Server

    Actions already taken:

    1. Enabled AWE on server

    2. Enabled settings to Lock Pages by SQL Server account using GP Editor

    3. Set Minimum Memory Usage=2048 MB & Maximum Usage=10240 MB & left 2 GB for OS

    Restarted server, now when checking using dm_os_memory_clerks but showing column 'awe_allocated_kb' values as 0.

    Please suggest where exactly lacking for enabling it. Kindly help.

    Regards,

    Ankur

  • 32 bit or 64 bit (OS and SQL)?

    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

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • Hi,

    Sorry forget to mention it...it's 32 bit system, madam.

    Regards,

    Ankur

  • Which edition of Windows 2003 SP2 are you using?

    Also, could you post the partition details from the boot.ini file on that server too?

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • Hi Perry,

    We have Windows 2003 Enterprise Edition with SP2. Contents in Boot.ini are mentioned below:-

    [boot loader]

    default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS /PAE

    timeout=30

    [operating systems]

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /noexecute=optout /fastdetect /PAE

    Let me know if you have any other query & thanks for the response.

    Regards,

    Ankur

  • ankur_libra (9/21/2011)


    [boot loader]

    default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS /PAE

    timeout=30

    [operating systems]

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /noexecute=optout /fastdetect /PAE

    With the DEP options set (/noexecute=optout) you dont need the /PAE switch, DEP automatically enables PAE.

    Are you sure you have set the locked pages in memory local security policy setting for the correct user account?

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • Hi Perry,

    So you mean to say, that in Boot.ini file:-

    --------------------------------------------------------------------------------

    [boot loader]

    default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS /PAE - ONLY HERE /PAE IS REQUIRED

    timeout=30

    [operating systems]

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    Please correct me if I am wrong?

    Yes, I have already set the locked pages in memory local security policy setting using the correct user account. On enabling AWE however I got error

    "Address Windowing Extensions (AWE) requires the 'lock pages in memory' privilege which is not currently present in the access token of the process."

    But after that when I checked it shows that AWE is enabled. Currently it is showing AWE as enabled.

    Also is DEP refers to Data Execution Prevention? If so, on server it is enabled for all programs.

    Kindly guide me, how to proceed further..

    Thanks,

    Regards,

    Ankur

  • ankur_libra (9/21/2011)


    Hi Perry,

    So you mean to say, that in Boot.ini file:-

    --------------------------------------------------------------------------------

    [boot loader]

    default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS /PAE - ONLY HERE /PAE IS REQUIRED

    if you have no DEP options set then yes

    ankur_libra (9/21/2011)


    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /sos /bootlog /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="HP SMP Preserved:Windows Server 2003, Enterprise" /noexecute=optout /fastdetect /PAE - HERE /PAE IS NOT REQUIRED

    Please correct me if I am wrong?

    not required here as you have specified DEP options which automatically enable PAE

    ankur_libra (9/21/2011)


    On enabling AWE however I got error

    "Address Windowing Extensions (AWE) requires the 'lock pages in memory' privilege which is not currently present in the access token of the process."

    this indicates that the policy has not been applied correctly. Login to SSMS and check the SQL Server log. If AWE is correctly enabled there will be a message in the log indicating that Address Windowing Extensions are in use

    ankur_libra (9/21/2011)


    Also is DEP refers to Data Execution Prevention? If so, on server it is enabled for all programs.

    yes it does, that's fine

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • Hi Perry,

    Thanks again for providing response. 🙂

    When I checked error log, there is only one message related to AWE i.e.

    " Set AWE Enabled to 1 in the configuration paramenters to allow use of more memory"

    & there is NO message stating that "Address Windowing Extensions are in use"

    But as stated earlier, when checking value of AWE using Sp_configure, it is showing as 1. Does it mean that AWE is not actually enabled on server...it's giving fake value ?

    Also kindly suggest how to proceed step by step so that AWE can be implemenetd successfully.

    Regards,

    Ankur

  • I believe Books Online has good instructions on how to enable AWE and large memory access on 32 bit systems. I would also look at dbcc memorystatus (documented online) for very detailed information about memory usage.

    Best,
    Kevin G. Boles
    SQL Server Consultant
    SQL MVP 2007-2012
    TheSQLGuru on googles mail service

  • Have you followed this article - http://msdn.microsoft.com/en-us/library/ms190673(v=sql.90).aspx

    Have you looked at the error logs to see - "Address Windowing Extensions enabled."

  • I believe the quote below is pretty descriptive of your problem

    ankur_libra (9/21/2011)


    On enabling AWE however I got error

    "Address Windowing Extensions (AWE) requires the 'lock pages in memory' privilege which is not currently present in the access token of the process."

    -----------------------------------------------------------------------------------------------------------

    "Ya can't make an omelette without breaking just a few eggs" 😉

  • Hi Perry,

    You are right...again checked server..last time server rebooted but no gains...then I remove & reset the 'lock pages in memeory' and 'Sp_configure AWE' settings.

    Last saturday, when again server rebooted...hurray...got AWE enabled message in Error log and now it's working perfectly,

    Thanks to you and all others for their valuable support. 🙂

    Regards,

    Ankur

  • Speaking directly to that, in case others run into it...

    You must ensure that the security context of the process running SQL Server has the right "Lock Pages in Memory" on the host. In more simple terms the account that runs the SQL Server service on the host needs this right or AWE will not function. The reason I reiterate this here explicitly is for those of you that work in more secured environments, with more robust Active Directory configurations, namely more specific Group Policy configurations. This, like any other internal host right, can be dictated by group policy.

    I've seen numerous situations where GPO* propigation that wasn't ran up the flag pole for evaluation by all concerned parties, or other similar situations result in this right being pulled out from under SQL's service account, breaking this.

    Just something to be aware of.

    *Group policy is probably way off scope for this forum. I won't clutter it with discussion of GP here. I can of course be contacted out of thread.

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