Post reply

awe_allocated_kb in SQL 2012

  • January 3, 2013 at 7:11 am

    #272409

    Hi,

    "awe_enabled" is removed from SQL Server 2012 than why "awe_allocated_kb" column exists in memory related DMVs like sys.dm_os_memory_clerks

    What will happen if I configure LPIM (Lock Page in Memory) on SQL 2012 64bit?

    Is SQL 2012 allocate memory which will not be pagable and count with Buffer Pool?

    with refer http://blogs.msdn.com/b/sqlosteam/archive/2012/07/12/memory-manager-configuration-changes-in-sql-server-2012.aspx

    Ram
    MSSQL DBA

  • January 3, 2013 at 7:24 am

    #1573315

    Hi,

    What will happen if I configure LPIM (Lock Page in Memory) on SQL 2012 64bit?

    I make the changes on my Testing SQL 2012, Yes memory allocating from AWE API. and It is not pagable (as AWE APIs deafult behaviar)

    Ram
    MSSQL DBA

  • January 3, 2013 at 7:37 am

    #1573327

    AWE enabled is for 32-bit SQL to access memory above the 4GB boundary. That's what's been removed.

    awe_memory is any that's allocated using the alloc_physical_memory API call, and that's used when locked pages is enabled on 64-bit instances. Hence why the column is still there.

    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

  • January 3, 2013 at 10:36 pm

    #1573584

    I agree with you.

    SQL 2008 & before any memory allocation >8KB will be allocated by MultiPageAllocation which was came from AWE_Memory (if AWE_Enabled & PLIM True).

    Now SQL 2012 any memory allocation will be allocated by single_memory_allocation (there is no MultipageAllocation). So if I enabled LPIM, how SQL server know from where he should allocate memory. whether from AWE or normal?

    And is AWE_memory part of Max Server Memory?

    Ram
    MSSQL DBA

  • January 4, 2013 at 2:20 am

    #1573643

    Ramdas Baghel (1/3/2013)

    Now SQL 2012 any memory allocation will be allocated by single_memory_allocation (there is no MultipageAllocation). So if I enabled LPIM, how SQL server know from where he should allocate memory. whether from AWE or normal?

    If you enable locked pages, you're telling SQL to lock all it's memory, meaning allocate all it's memory with the physical alloc API call. Hence it'll be AWE memory

    And is AWE_memory part of Max Server Memory?

    Of course it is.

    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

Viewing 5 posts - 1 through 4 (of 4 total)

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