Posted on 2010-01-06
I have a system which yesterday had several short dumps for pxa_no_free_space.
Looking at the size of the abap/buffersize it is currently set to 400MB. However if I look at the history of the buffering I can see it buffers a lot in a day. Since the system was started on the 13/12/2009 it has buffered just over 2,8million entries. The daily amount of swopping seems to vary between 13000 - 400000 swops.
As per note 103747 the following comment is made about buffer swaps.
"A few thousand swaps can be tolerated each day, but if you find more than 10000 swaps per day, you should enlarge the buffer. Note also that importing ABAP programs leads to the buffer being fragmented, which then leads to swaps. Therefore, reduce the number of imports in your production system"
This makes me think the buffer size should be increased to 450mb or even 500mb in size. However my question is this. Looking at st02 you can see the following.
Size Allocated KB 400.000
Available KB 371.692
Used KB 370.642
Free KB 1.050
Gaps KB 1.098
Directory entries Available 100.000
As you can see the free directory entries are 88,7% what is the relevance of this to the buffering? And is this the value of 88,7% the maximum value that was used or the current value?
Also looking at the bufferize there is 400mb allocated but only 371mb available which in turn is us utilized at 370mb. What would your recommendations on this be?