datanode + Error occurred during initialization of VM Too small initial heap

[#1]

we restart the dastanodes on our cluster ( HDP - 2.6.4 )

but datanode failed on

Error occurred during initialization of VM
Too small initial heap

this is strange because dtnode_heapsize is 8G ( DataNode maximum Java heap size = 8G )

capture.png

so we not understand how it can be

dose - initial heap size related to dtnode_heapsize ?

Java HotSpot(TM) 64-Bit Server VM (25.112-b15) for linux-amd64 JRE (1.8.0_112-b15), built on Sep 22 2016 21:10:53 by "java_re" with gcc 4.3.0 20080428 (Red Hat 4.3.0-8)
Memory: 4k page, physical 197804180k(12923340k free), swap 16777212k(16613164k free)
CommandLine flags: -XX:ErrorFile=/var/log/hadoop/hdfs/hs_err_pid%p.log -XX:GCLogFileSize=1024000 -XX:InitialHeapSize=8192 -XX:MaxHeapSize=8192 -XX:MaxNewSize=209715200 -XX:MaxTenuringThreshold=6 -XX:NewSize=209715200 -XX:NumberOfGCLogFiles=5 -XX:OldPLABSize=16 -XX:ParallelGCThreads=4 -XX:+PrintAdaptiveSizePolicy -XX:+PrintGC -XX:+PrintGCDateStamps -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintTenuringDistribution -XX:+UseCompressedClassPointers -XX:+UseCompressedOops -XX:+UseConcMarkSweepGC -XX:+UseGCLogFileRotation -XX:+UseParNewGC 
==> /var/log/hadoop/hdfs/hadoop-hdfs-datanode-worker01.sys242.com.out <==
Error occurred during initialization of VM
Too small initial heap
ulimit -a for user hdfs
core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 772550
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 128000
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 65536
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

[#2 · Accepted solution]

You are missing "m", like 8192m, without "m" the unit is byte, so only 8 kilobytes! Also note that 4G is usually enough for DN heap.