Help Me!! - AIX box utilised 100% memory for whole day

Hi,

As i am new to AIX,I have a problem one of my AIX box shows 100% memory utilization for a whole day.How to find the root cause..

Note : it is a DB2 8.1 DB server.

Please help Me!!:confused:

That is totally normal on AIX since it usually uses RAM that is not needed by processes to cash files, so that reads/writes to physical disks are reduced.

If you "paging space ins", you have a real problem as paging is slowing down your system very noticable. You can check it for example with vmstat and look for the columns pi and po (ie. "paging space in" and "paging space out"). If there is about nothing paged in, your memory should be allright.

There is lots of documentation and how to tune this (if needed) on the web. Search for:
VMM, vmo, lru_file_repage, maxperm, minperm, ...

What zaxxon said is absolutely correct. Here is another very very quick check if everything is ok with your memory (and, no, it is neither an in-depth analysis nor does it replace one): Issue the command "svmon -G" and observe the first line of output. Here is a sample:

# svmon -G

         size  inuse free   pin virtual
memory 262133 261991  142 11851  128713

I have marked bold the two relevant values. As long as "inuse" is higher or roughly equal to "virtual" everything is ok with the memory size. If "virtual" is (much) higher than "inuse" then your machine needs a memory upgrade - and the size of the upgrade will be at about the difference betweeen these two values, times 4k, as the numbers represent 4k-sized memory-pages.

I hope this helps.

bakunin