Unable to lock JVM Memory error= – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 2.3-2.3

Briefly, this error occurs when Elasticsearch is unable to lock the JVM memory due to insufficient system settings. This can lead to swapping issues, which can severely degrade performance. To resolve this, you can disable swapping entirely on your system. Alternatively, you can configure Elasticsearch to lock the memory by setting ‘bootstrap.memory_lock’ to true in the Elasticsearch configuration file. Also, ensure that the user running Elasticsearch has permissions to lock memory in the ‘limits.conf’ file. Lastly, verify that you have enough physical memory available on your system.

This guide will help you check for common problems that cause the log ” Unable to lock JVM Memory: error= ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: bootstrap.

Log Context

Log “Unable to lock JVM Memory: error=” classname is JNANatives.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

             // this will have already been logged by CLibrary; no need to repeat it

        // mlockall failed for some reason
        logger.warn("Unable to lock JVM Memory: error=" + errno + ";reason=" + errMsg);
        logger.warn("This can result in part of the JVM being swapped out.");
        if (errno == JNACLibrary.ENOMEM) {
            if (rlimitSuccess) {
                logger.warn("Increase RLIMIT_MEMLOCK; soft limit: " + rlimitToString(softLimit) + "; hard limit: " + rlimitToString(hardLimit));
                if (Constants.LINUX) {


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