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  • Question

  • Hi

     

    We are planning to migrate our current production server to a new better server. Currently all the database live on a single instance, what we planning is install 2 sql server instance one for internal applications databases and on the 2<sup>nd</sup> instance all the databasess of 3<sup>rd</sup> party application we use.  

     

    Spec

     

    Windows 2008 x64 enterprise

    SQL Server 2008 x64 R2 Slandered

    Memory 128 GB

     

    As you know sql 2008 std edition can only go up to 64 GB, my question if i install it as 2 instance,   will these instance be sharing the   same 64 gb memory area.

     

     

    thanks

     

    Friday, October 15, 2010 1:36 PM

Answers

  • Hello,

    The second instance won’t address the same 64 GB that the first instance is addressing. When you configure the Min/max server memory configuration on each instance you are not configuring the same address space.

    Hope this helps.   
     
    Regards,

    Alberto Morillo
    SQLCoffee.com

    • Marked as answer by SimpleSQL Monday, October 18, 2010 4:16 PM
    Monday, October 18, 2010 1:03 PM

All replies

  • Hello,

    Each instance allocates its own memory.

    It is recommended to set the “max server memory” and “min server memory” when you have multiple instances installed on a server. Please do this even when you know Standard Edition is limited to 64 GB.

    http://msdn.microsoft.com/en-us/library/ms178067.aspx  (Running Multiple Instances of SQL Server)

    Hope this helps.   
     
    Regards,

    Alberto Morillo
    SQLCoffee.com

    Friday, October 15, 2010 2:34 PM
  • Hi

     

    Thanks for ur reply.. yes i know each instance allocate its own memory.   My understanding of sql server memory allocation is sql std can access 0 to 64 gb of memory address but not above the 64 gb memory region. So by installing two instance both  should be able to access 0 to 64 memory region.. right..??... when you specifying min and max memory, is that allocate is going be within the 0-64 address space..??? if so isn’t it that sharing the same address area..

    Also assume a poor query runs on instance 1 that need to utilises the full   memory(up to 64) and now at the same time another query runs on instance 2.Instance 1 is now using the 0-64 gb memory area. How sql server or os handle such situation.    

    Thanks

     

     

     

     

     

     

    Monday, October 18, 2010 8:39 AM
  • Hello,

    The second instance won’t address the same 64 GB that the first instance is addressing. When you configure the Min/max server memory configuration on each instance you are not configuring the same address space.

    Hope this helps.   
     
    Regards,

    Alberto Morillo
    SQLCoffee.com

    • Marked as answer by SimpleSQL Monday, October 18, 2010 4:16 PM
    Monday, October 18, 2010 1:03 PM
  •  

    HiYes  its clear now..

     

    thanks

    Monday, October 18, 2010 4:16 PM