Error in XPACK elasicsearch

[Vivek_Nigam]

While running XPack elasicserch getting following error:

./elasticsearch

[2017-12-06T03:18:26,851][INFO ][o.e.n.Node ] [] initializing ...
[2017-12-06T03:18:26,883][WARN ][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main]
org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: failed to obtain node locks, tried [[/home/elkstack/elasticsearch-6.0.0/data/elasticsearch]] with lock id [0]; maybe these locations are not writable or multiple nodes were started without increasing [node.max_local_storage_nodes] (was [1])?
at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:134) ~[elasticsearch-6.0.0.jar:6.0.0]

[dadoonet (David Pilato)]

Most of the time this is happening when you start by mistake 2 instances of elasticsearch using the same data folder.

Check what is running.

[Vivek_Nigam]

hi , following files available under given locations:

/home/elkstack/elasticsearch-6.0.0/data/nodes/0

drwxrwxrwx 13 nds nds 4096 Dec 5 05:31 indices
-rwxrwxrwx 1 nds nds 0 Dec 5 00:34 node.lock
drwxrwxrwx 2 nds nds 41 Dec 5 04:03 _state

[dadoonet (David Pilato)]

Yes. But are the running processes?

[zqc0512 (andy_zhou)]

stop all es and start.
like running two es instances.

[Vivek_Nigam]

Please help me to check all running process in elasticsearch 6

Also how to stop the running process.

i check through following command:

[root@elkstack _state]# ps aux | grep 'elastic'
root 3649 0.0 0.0 112644 952 pts/4 S+ 06:48 0:00 grep --color=auto elastic