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Simon_L
Starting Member
32 Posts |
 Posted - 2008-10-20 : 10:31:00
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| Again a moment when all is running smoothly so time to reflect / brush up on knowledge etc etc I have a couple of questions regarding perfmon ,,,Did I imagine it or did SQLServer: buffer Manager used to have a counter called Free buffers ??and Total Server Memory .. is this not the same as overall server memory ?? thank you Simon |
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SimpleSQL
Yak Posting Veteran
85 Posts |
Posted - 2008-10-21 : 12:51:32
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| SQL Server Buffer Manager has 'Free Pages' counter which tells you number of 8KB free pages in buffer pool.Total Server memory is the current size of buffer pool and is not neccesarily total memory on the machine. It would typically be close to max server memory paramenter, if it is set (other than default) or will be close to total machine memeory (depends on SQL's memory requirements). This value is managed dynamically and grow and shrik and will not be more than total server memory. |
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Simon_L
Starting Member
32 Posts |
Posted - 2008-10-22 : 05:36:22
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| Ok if I understand correctlyAvaible bytes is the amount of memory availabe to SQL at that point in timeWorking Set is the amount SQL is actual usingTotal server memory is the toal amount amount of memory all porcesses (including SQL) on that server are using...so far so good...I have (on a 4gb box with 3 gb fixed size set aside for SQL )available bytes = 1.46gbworking set = 1.65 gbtotal server = 1.58 gbSo how is SQL using more memory than all the ohter processes and itself ?! i.e working set > total server |
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SimpleSQL
Yak Posting Veteran
85 Posts |
Posted - 2008-10-23 : 04:03:06
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| Ok if I understand correctlyAvaible bytes is the amount of memory availabe to SQL at that point in time[SimpleSQL] If you are refering to 'Available Bytes' 'Memory' object counter, than Available Bytes is the memory available to machine at a point in time. There is no 'Availble Bytes' caounter for SQL Server.Working Set is the amount SQL is actual using[SimpleSQL] Workign set is the actual Physical memory, SQL could be using more (that is SQL memory paged out)Total server memory is the toal amount amount of memory all porcesses (including SQL) on that server are using...[SimpleSQL] Correction, Total Memory is the size of SQL Server Buffer pool at a given point in time, it is not total memory used by all the processes. Again I am refeeing to SQL Server Memory Manager object --> Tota Server Memory counter.so far so good...I have (on a 4gb box with 3 gb fixed size set aside for SQL )available bytes = 1.46gb <-- Amount of memory availble to machineworking set = 1.65 gb <-- Amount of physical memory used by SQL Server (Assuming this is SQL workign set and not total working set for all processes). This includes Buffer Pool and a region of memory called MTL (MemToLeave) and hence it can be more than total server memorytotal server = 1.58 gb <-- Size of Buffer Pool, there are other components in SQL Server memory other than buffer pool.So how is SQL using more memory than all the ohter processes and itself ?! i.e working set > total server[SimpleSQL] Workign set for SQL Server process is physical memory usage of SQL Server process. Total Server memory is Buffer pool (subset of SQL Server memory), so it is possible for working set to be larger than total server memory. I think you are confusing total server memory for SQL Server with actual amout of physical RAM on machine. |
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Simon_L
Starting Member
32 Posts |
Posted - 2008-10-23 : 11:55:53
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| once again thank you :-)simon |
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Permon Counters .. free buffers and total server m