DB2 Database background processes stop unexpectedly

Issue

• We have two DB2 HADR clusters that have had background processes no longer starting after the OS was upgraded.
• For both clusters, there were no issues on RHEL5.7. After an upgrade to RHEL 5.9 on both clusters, however, the issue started.
• This behavior is not observed on any other DB2 database server, only these clusters in production.