After APM agent instrumentation, WebLogic instance under Red Hat Linux shows this non-fatal message at startup: "Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 22)"

Products

• CA Application Performance Management Agent (APM / Wily / Introscope)
• INTROSCOPE

Issue/Introduction

After APM agent instrumentation, WebLogic instance under Red Hat Linux shows this non-fatal message at startup:

Java HotSpot(TM) 64-Bit Server VM warning: Failed to reserve shared memory (errno = 22)

Environment

APM 9.x, 10.x Java AgentWebLogic Server under Red hat Linux

Cause

Cause is unrelated to APM Agent. The option "-XX:+UseLargePages" had been included the JVM arguments which requires explicit hugepages (libhugetlbfs) to be setup on the Red Hat Linux OS.

Resolution

EITHER:

Ensure that the explicit hugepages (libhugetlbfs) setup on the Red Hat Linux OS is complete and accessible for the userid running the WebLogic instance.

OR:

Remove the argument "-XX:+UseLargePages"

Additional Information

For further information including advantages/disadvantages of the Java large pages options see: Oracle Java 8 documentation

Red hat Customer Portal: How do I enable large page support on Linux?