Admins,
I received two replys on the output of ipcs -am and shared memory allocation.
1)
Yep your theory is right. The output of the columns is in bytes and it
should be about 80 to 85 % of physical memory. The rest being used by
the system and programs.
If you see both page ins and page outs then yes your systems is most
likely short on memory. But remember that pi and po can also occur on
memory mapped files. But there, most of the times one see either page
ins or page outs.
If you see 20-50 free pages then yes, you problably have a memory
problem. The operating system tries to keep the amount of free pages
something like at 1000 for every 512MB of memory ( this also could be
for every 1024 MB not sure exactly).
So your system is swapping the shared memory. Most of the times this is
very bad because most programs expect the shared memory to be in memory.
They use it either for cache or tempory data and expext it to be there
for several processes to use. Biggest performance gain is to lower the
amount of shared memory used.
You didn't follow some advice of SAP for tuning did you :).
regards
udo de boer
2)
Not very familiar with SAP, however I did check some of the ubc
params that we have set up and ubc-minpercent = 1 (default 10) and
ubc-maxpercent = 10 (default 100). Also, you might check your
per-proc-data-size and per-proc-address-space and see what those values are.
On our systems we have those 2 values and the max-per-proc-data-size and
max-per-proc-address-space equal to physical memory. However, these are on
boxes running various levels of Oracle so I do not know how these params
will behave with SAP, but since it is a test environment try it and see.
HTH,
Chris Bryant
Thanks to both replys!!!
If anyone else has input please feel free to drop me a line.
Lee Brewer
Received on Thu Mar 14 2002 - 13:16:30 NZDT