Sun Java System Application Server Enterprise Edition 8.2 Release Notes

Shared memory segments locked and cannot be paged out. (ID 5052548)


HADB 4.3-0.16 and later is configured to use Intimate Shared Memory when it creates and attaches to its shared memory segments (uses the SHM_SHARE_MMU flag). The use of this flag essentially locks the shared memory segments into physical memory and prevents them from being paged out. This can easily cause problems with installations on low end machines.

Therefore if a developer has a machine with 512MB of memory and plenty of swap space available when using Application Server7.0 EE, and then installed 7.1 EE or later, he or she will encounter problems configuring the default clsetup cluster (which creates two HADB nodes, each with a devicesize of 512, which results in there not being enough physical RAM to support the shared memory that both nodes require.


Make sure you have the recommended amount of memory when co-locating Application Server and HADB. See HADB Requirements and Supported Platforms for more information.