Comment 4 for bug 1780948

I see this on system.log on config-cassandra.

WARN [main] 2018-07-12 09:26:12,892 NativeLibrary.java:187 - Unable to lock JVM memory (ENOMEM). This can result in part of the JVM being swapped out, especially with mmapped I/O enabled. Increase RLIMIT_MEMLOCK or run Cassandra as root.

[root@nodec7 sangupta]# free -g
              total used free shared buff/cache available
Mem: 31 25 0 0 4 5
Swap: 0 0 0

[root@nodec7 sangupta]# top -o %MEM

top - 00:12:05 up 10:23, 4 users, load average: 0.35, 0.61, 0.66
Tasks: 346 total, 1 running, 345 sleeping, 0 stopped, 0 zombie
%Cpu(s): 20.6 us, 2.9 sy, 0.0 ni, 76.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st
KiB Mem : 32753116 total, 1031864 free, 26521596 used, 5199656 buff/cache
KiB Swap: 0 total, 0 free, 0 used. 5721816 avail Mem

The VM is all-in-one setup and looks under resourced. Have you been running all-in-one on this setup earlier?