Unexpected growth in paging space utilization might occur on a DB2 or AIX system where sufficient memory exists to keep DB2 application memory in RAM. This might be observed on DB2 or AIX systems using medium (64K) memory pages. While the performance effects from the paging itself should be negligible, paging space might become exhausted over time. This condition typically results in an outage, such as system hang or terminated applications.
Two AIX defects have been identified. This problem is resolved by AIX APAR IZ67445 - 64K PAGING TAKING PLACE WHEN AVAILABLE SYSTEM RAM EXISTS (affects AIX 5.3 and AIX 6.1). and AIX HIPER APAR IZ92561 - 64K KERNEL HEAP CAUSES PAGING WHEN RAM IS OTHERWISE AVAILABLE (impacts AIX 6.1 only).
This is covered in detail by the technical article 1417752 , http://www.ibm.com/support/docview.wss?uid=swg21417752