on 10-14-2014 3:49 PM
Hello,
I have a client who is experiencing some performance issues so I'm just reviewing the memory parameters/allocations.
Environment is Windows/SQL.
The box has 8GB of physical memory with 24GB of virtual memory.
em/initial_size_MB is set to 10GB.
I have in the back of my mind that em/initial_size_MB should not be greater than the amount of physical memory. Is that correct? And if it's set to a higher value, what issues could it cause?
Many thanks.
Hi Paul ,
Check the below sap note
88416 - Zero administration memory management for the ABAP server
The parameter above has some limitation for kernel as well.
For the same checked the sapnote
1458065 - Extended memory restricted to 64G
835474 - More than 32 GB extended memory
With Regards
Ashutosh Chaturvedi
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
Thanks for the suggestions.
So note 88416 suggests that em/initial_size_MB should be equal to PHYS_MEMSIZE??
PHYS_MEMSIZE does not exist in this particular system.
Presumably it will just be the value of the of the amount of RAM in the box?
In which, I need to be reducing em/initial_size_MB to 8GB?
The SAP note 88416 - Zero administration memory management for the ABAP server suggested by Ashutosh is the answer. If the parameter PHYS_MEMSIZE is not set then you should set it.
1926986 - Best practice formulas in profile maintenance
RB
Hi Paul
As per the SAP stranded you have to set the memory 70% Application & 30% Database.
1. In your MS SQL server memory resource should not cross more than 30 % of memory? If it is yes, you can set the memory parameters in MS SQL MMC
2. Balance amount 70% of memory can be used for application & OS
3. You can restart the system check the transaction code ST02 memory & buffer usage Is this any swaps?
4. Check the DB over all usage? refer the SCN link how you can fine trun the DB?
Regards
Sriram
Hi,
These are all extremely helpful replies, thank you.
I can pad this out now with a little bit more information. PHYS_MEMSIZE is set, I was searching RZ11 for PHYS* - this doesn't work. Putting in the PHYS_MEMSIZE does!
This is set to 10GB. I don't see how as this is automatically set from the amount of RAM in the box right? And that is 8GB!
Also, ST04 shows 3GB is fixed. So only 5GB left to play with. But PHYS_MEMSIZE and em/initial_size_MB is set to 10GB.
All a bit messy really.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
Hi Paul,
em/initial_size_MB value should never be more the physical memory available to the SAP instance.
PHYS_MEMSIZE:
If you have only SAP instance running on the host than you don't need to set the value for it.
Else set it accordingly to available space
Formula:
PHYS_MEMSIZE = Available main memory for the SAP instance
The default value for PHYS_MEMSIZE is the size of the main memory in MB, that is, it is adjusted automatically when the main memory configuration is changed.
em/initial_size_MB = [PHYS_MEMSIZE]
If required, the extended memory extends itself by the value [PHYS_MEMSIZE / 2].
Example: Application server with 1 GB main memory.
PHYS_MEMSIZE is not maintained and its default value is the size of the main memory. This means that the initial size of the extended memory = 1 GB. If this size is not sufficient, the extended memory is increased in 500 MB steps until the maximum size em/max_size_MB (default: 20 GB) is reached or until there is no more address space in the NT page file.
Hope this helps you out.
Regards,
Prithviraj
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
User | Count |
---|---|
89 | |
10 | |
10 | |
10 | |
7 | |
6 | |
6 | |
5 | |
4 | |
3 |
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.