# Could not find or load main class org.elasticsearch.tools.launchers.JavaVersionChecker **URL:** \ **Category:** Elasticsearch\ **Created:** [February 15, 2018, 5:52pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046 "2018-02-15T17:52:22Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![lengthy\_preamble](https://avatars.discourse-cdn.com/v4/letter/l/e47774/32.png) [@lengthy\_preamble](https://discuss.elastic.co/u/lengthy_preamble)\ **Post date:** [February 15, 2018, 5:52pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/1 "2018-02-15T17:52:22Z")
I'm using CentOS and have downloaded Elasticsearch 6.2.1. I created a new user "elastic" and when I run ./bin/elasticsearch I get the error: Could not find or load main class org.elasticsearch.tools.launchers.JavaVersionChecker I placed this user in the "wheel" group, since I'm led to understand that this group has admin privileges without acting as root. If I try it with "sudo ./bin/elasticsearch" I get: [2018-02-15T17:42:39,776][WARN][o.e.b.ElasticsearchUncaughtExceptionHandler] [] uncaught exception in thread [main] org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:125) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:112) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:124) ~[elasticsearch-cli-6.2.1.jar:6.2.1] at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:85) ~[elasticsearch-6.2.1.jar:6.2.1] Caused by: java.lang.RuntimeException: can not run elasticsearch as root at org.elasticsearch.bootstrap.Bootstrap.initializeNatives(Bootstrap.java:105) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:172) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:323) ~[elasticsearch-6.2.1.jar:6.2.1] at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:121) ~[elasticsearch-6.2.1.jar:6.2.1] I searched a bit and saw that it this error can be due to the java version, but it seems to be up to date: [elastic@sandbox-hdp elasticsearch-6.1.1]$ sudo update-alternatives --config java There are 3 programs which provide 'java'. ## Selection Command 1 /usr/lib/jvm/jre-1.7.0-openjdk.x86\_64/bin/java \*+ 2 /usr/lib/jvm/jre-1.8.0-openjdk.x86\_64/bin/java 3 /usr/lib/jvm/jre-1.5.0-gcj/bin/java Any suggestions? ---
**Author:** ![lengthy\_preamble](https://avatars.discourse-cdn.com/v4/letter/l/e47774/32.png) [@lengthy\_preamble](https://discuss.elastic.co/u/lengthy_preamble)\ **Post date:** [February 17, 2018, 3:24pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/2 "2018-02-17T15:24:32Z")
I hate to bump a thread but I'm unable to get this to work and I'm not sure what else I can do. I know these errors are often configuration-based and can be a hassle to troubleshoot, but I need to get this working. Does anyone have any suggestions? This is on a Hortonworks HDP VM, so I don't know the ins and outs of how they've configured java on this system. Any assistance would be appreciated. ---
**Author:** ![jasontedor](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jasontedor/32/66992_2.png) [@jasontedor](https://discuss.elastic.co/u/jasontedor)\ **Post date:** [February 17, 2018, 6:43pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/3 "2018-02-17T18:43:36Z")
The message here is clear: ```auto org.elasticsearch.bootstrap.StartupException: java.lang.RuntimeException: can not run elasticsearch as root ``` This is because you are executing the startup script as root. Let us not do that to avoid this problem. Next, would you please move your Elasticsearch installation off of `/` and put it in `/home/elastic/`? If this still causes trouble, would you execute: ```auto $ bash -x /home/elastic/elasticsearch-6.2.1/bin/elasticsearch ``` and we will start debugging from there. ---
**Author:** ![lengthy\_preamble](https://avatars.discourse-cdn.com/v4/letter/l/e47774/32.png) [@lengthy\_preamble](https://discuss.elastic.co/u/lengthy_preamble)\ **Post date:** [February 17, 2018, 10:11pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/4 "2018-02-17T22:11:55Z")
Thank you for the assistance, jasontedor...it appears to be working. At least, I think so...sorry this is for a course and I'm still getting familiar with elasticsearch. The output so far (when I run the elasticsearch command) is as follows: [2018-02-17T22:03:39,314][INFO][o.e.n.Node] [] initializing ... [2018-02-17T22:03:39,396][INFO][o.e.e.NodeEnvironment] [LSVW6GD] using [1] data paths, mounts [[/ (overlay)]], net usable\_space [19.8gb], net total\_space [42.6gb], types [overlay] [2018-02-17T22:03:39,397][INFO][o.e.e.NodeEnvironment] [LSVW6GD] heap size [990.7mb], compressed ordinary object pointers [true] [2018-02-17T22:03:39,400][INFO][o.e.n.Node] node name [LSVW6GD] derived from node ID [LSVW6GD2RUm2Cdo0B6p1eA]; set [node.name] to override [2018-02-17T22:03:39,400][INFO][o.e.n.Node] version[6.2.1], pid[2532], build[7299dc3/2018-02-07T19:34:26.990113Z], OS[Linux/4.4.114-1.el7.elrepo.x86\_64/amd64], JVM[Oracle Corporation/OpenJDK 64-Bit Server VM/1.8.0\_161/25.161-b14] [2018-02-17T22:03:39,401][INFO][o.e.n.Node] JVM arguments [-Xms1g, -Xmx1g, -XX:+UseConcMarkSweepGC, -XX:CMSInitiatingOccupancyFraction=75, -XX:+UseCMSInitiatingOccupancyOnly, -XX:+AlwaysPreTouch, -Xss1m, -Djava.awt.headless=true, -Dfile.encoding=UTF-8, -Djna.nosys=true, -XX:-OmitStackTraceInFastThrow, -Dio.netty.noUnsafe=true, -Dio.netty.noKeySetOptimization=true, -Dio.netty.recycler.maxCapacityPerThread=0, -Dlog4j.shutdownHookEnabled=false, -Dlog4j2.disable.jmx=true, -Djava.io.tmpdir=/tmp/elasticsearch.KDEQJoCy, -XX:+HeapDumpOnOutOfMemoryError, -XX:+PrintGCDetails, -XX:+PrintGCDateStamps, -XX:+PrintTenuringDistribution, -XX:+PrintGCApplicationStoppedTime, -Xloggc:logs/gc.log, -XX:+UseGCLogFileRotation, -XX:NumberOfGCLogFiles=32, -XX:GCLogFileSize=64m, -Des.path.home=/home/elastic3/elasticsearch-6.2.1, -Des.path.conf=/home/elastic3/elasticsearch-6.2.1/config] [2018-02-17T22:03:40,111][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [aggs-matrix-stats] [2018-02-17T22:03:40,111][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [analysis-common] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [ingest-common] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [lang-expression] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [lang-mustache] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [lang-painless] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [mapper-extras] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [parent-join] [2018-02-17T22:03:40,112][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [percolator] [2018-02-17T22:03:40,113][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [rank-eval] [2018-02-17T22:03:40,113][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [reindex] [2018-02-17T22:03:40,113][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [repository-url] [2018-02-17T22:03:40,113][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [transport-netty4] [2018-02-17T22:03:40,113][INFO][o.e.p.PluginsService] [LSVW6GD] loaded module [tribe] [2018-02-17T22:03:40,114][INFO][o.e.p.PluginsService] [LSVW6GD] no plugins loaded [2018-02-17T22:03:43,037][INFO][o.e.d.DiscoveryModule] [LSVW6GD] using discovery type [zen] [2018-02-17T22:03:43,638][INFO][o.e.n.Node] initialized [2018-02-17T22:03:43,638][INFO][o.e.n.Node] [LSVW6GD] starting ... [2018-02-17T22:03:43,861][INFO][o.e.t.TransportService] [LSVW6GD] publish\_address {127.0.0.1:9300}, bound\_addresses {127.0.0.1:9300} [2018-02-17T22:03:43,874][WARN][o.e.b.BootstrapChecks] [LSVW6GD] max number of threads [1024] for user [elastic] is too low, increase to at least [4096] [2018-02-17T22:03:43,875][WARN][o.e.b.BootstrapChecks] [LSVW6GD] max virtual memory areas vm.max\_map\_count [65530] is too low, increase to at least [262144] [2018-02-17T22:03:46,965][INFO][o.e.c.s.MasterService] [LSVW6GD] zen-disco-elected-as-master ([0] nodes joined), reason: new\_master {LSVW6GD}{LSVW6GD2RUm2Cdo0B6p1eA}{d7nLDjVWQLCktRTN62E\_aQ}{127.0.0.1}{127.0.0.1:9300} [2018-02-17T22:03:46,970][INFO][o.e.c.s.ClusterApplierService] [LSVW6GD] new\_master {LSVW6GD}{LSVW6GD2RUm2Cdo0B6p1eA}{d7nLDjVWQLCktRTN62E\_aQ}{127.0.0.1}{127.0.0.1:9300}, reason: apply cluster state (from master [master {LSVW6GD}{LSVW6GD2RUm2Cdo0B6p1eA}{d7nLDjVWQLCktRTN62E\_aQ}{127.0.0.1}{127.0.0.1:9300} committed version [1] source [zen-disco-elected-as-master ([0] nodes joined)]]) [2018-02-17T22:03:46,994][INFO][o.e.h.n.Netty4HttpServerTransport] [LSVW6GD] publish\_address {127.0.0.1:9200}, bound\_addresses {127.0.0.1:9200} [2018-02-17T22:03:46,994][INFO][o.e.n.Node] [LSVW6GD] started [2018-02-17T22:03:47,008][INFO][o.e.g.GatewayService] [LSVW6GD] recovered [0] indices into cluster\_state ---
**Author:** ![jasontedor](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jasontedor/32/66992_2.png) [@jasontedor](https://discuss.elastic.co/u/jasontedor)\ **Post date:** [February 17, 2018, 10:30pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/5 "2018-02-17T22:30:54Z")
> [@lengthy\_preamble](#): > > Thank you for the assistance, jasontedor...it appears to be working. Yup, that looks good, your node is running! I am happy to have helped. Best wishes. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 17, 2018, 10:31pm UTC](https://discuss.elastic.co/t/could-not-find-or-load-main-class-org-elasticsearch-tools-launchers-javaversionchecker/120046/6 "2018-03-17T22:31:05Z")
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