# Understanding Xms Xmx options **URL:** \ **Category:** Elasticsearch\ **Created:** [July 27, 2011, 3:56pm UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977 "2011-07-27T15:56:48Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![fucema](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/fucema/32/3160_2.png) [@fucema](https://discuss.elastic.co/u/fucema)\ **Post date:** [July 27, 2011, 3:56pm UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977/1 "2011-07-27T15:56:48Z")
I'm trying to better understand the memory options for Elastic Search. I was pretty confident until I looked at the process details recently. I start a node using this command: bin/elasticsearch -f -Xms5g -Xmx5g Here is the resulting process details: elastic 32361 10.3 34.3 5696452 5602468 pts/2 SLl+ 10:59 0:04 /usr/bin/java -Xms256m -Xmx1g -Xss128k -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+HeapDumpOnOutOfMemoryError -Delasticsearch -Des.path.home=/usr/local/elastic/elasticsearch -Des-foreground=yes -cp :/usr/local/elastic/elasticsearch/lib/elasticsearch-0.17.2.jar:/usr/local/elastic/elasticsearch/lib/_:/usr/local/elastic/elasticsearch/lib/sigar/_ -Xms5g -Xmx5g org.elasticsearch.bootstrap.ElasticSearch Is the Xms/Xmx setting defining the memory space that is allocated outside of the jvm heap? The java executable looks like its set to -Xms256m -Xmx1g. It looks like my command line options do not affect the java memory parameters. I've also tried exporting ES\_MIN\_MEM and ES\_MAX\_MEM but I don't see any differences in the process details. ---
**Author:** ![fucema](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/fucema/32/3160_2.png) [@fucema](https://discuss.elastic.co/u/fucema)\ **Post date:** [July 27, 2011, 4:04pm UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977/2 "2011-07-27T16:04:27Z")
Oops I stand corrected on the last part: when I export ES\_MIN/MAX\_MEM settings and start up elastic search, the java memory settings reflect the memory settings I defined in the environment variables. So the problem stands with the command line memory settings. It gets a little more confusing when I set both the environment variables ES\_MIN\_MEM and ES\_MAX\_MEM and also specify memory settings from the command line. export ES\_MIN\_MEM=2g export ES\_MAX\_MEM=2g bin/elasticsearch -f -Xms3g -Xmx3g What is going on with the memory settings here? Here are the process details: elastic 5131 30.5 21.2 3557832 3461188 pts/3 SLl+ 12:01 0:02 /usr/bin/java -Xms2g -Xmx2g -Xss128k -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+HeapDumpOnOutOfMemoryError -Delasticsearch -Des.path.home=/usr/local/elastic/elasticsearch -Des-foreground=yes -cp :/usr/local/elastic/elasticsearch/lib/elasticsearch-0.17.2.jar:/usr/local/elastic/elasticsearch/lib/_:/usr/local/elastic/elasticsearch/lib/sigar/_ -Xms3g -Xmx3g org.elasticsearch.bootstrap.ElasticSearch ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [July 27, 2011, 5:04pm UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977/3 "2011-07-27T17:04:47Z")
It is being passed, check at the end of the command. The last memory settings used are the ones that are applied, and the script makes use of that fact. You can easily see the memory settings elasticsearch was started with using the nodes info API. On Wed, Jul 27, 2011 at 7:04 PM, S Lee [fucema@gmail.com](mailto:fucema@gmail.com) wrote: > Oops I stand corrected on the last part: when I export ES\_MIN/MAX\_MEM > settings and start up Elasticsearch, the java memory settings reflect the > memory settings I defined in the environment variables. > > So the problem stands with the command line memory settings. > > It gets a little more confusing when I set both the environment variables > ES\_MIN\_MEM and ES\_MAX\_MEM and also specify memory settings from the command > line. > > export ES\_MIN\_MEM=2g > export ES\_MAX\_MEM=2g > > bin/elasticsearch -f -Xms3g -Xmx3g > > What is going on with the memory settings here? > > Here are the process details: > > elastic 5131 30.5 21.2 3557832 3461188 pts/3 SLl+ 12:01 0:02 > /usr/bin/java -Xms2g -Xmx2g -Xss128k -XX:+UseParNewGC > -XX:+UseConcMarkSweepGC -XX:+CMSParallelRemarkEnabled -XX:SurvivorRatio=8 > -XX:MaxTenuringThreshold=1 -XX:CMSInitiatingOccupancyFraction=75 > -XX:+UseCMSInitiatingOccupancyOnly -XX:+HeapDumpOnOutOfMemoryError > -Delasticsearch -Des.path.home=/usr/local/elastic/elasticsearch > -Des-foreground=yes -cp > :/usr/local/elastic/elasticsearch/lib/elasticsearch-0.17.2.jar:/usr/local/elastic/elasticsearch/lib/_:/usr/local/elastic/elasticsearch/lib/sigar/_ > -Xms3g -Xmx3g org.elasticsearch.bootstrap.Elasticsearch ---
**Author:** ![fucema](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/fucema/32/3160_2.png) [@fucema](https://discuss.elastic.co/u/fucema)\ **Post date:** [July 27, 2011, 5:08pm UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977/4 "2011-07-27T17:08:11Z")
Ok, it is a little confusing because the java binary has 2g memory settings but the 3g settings are also listed at the end. Starts with: /usr/bin/java -Xms2g -Xmx2g -Xss128k ... Ends with: ... -Xms3g -Xmx3g org.elasticsearch.bootstrap.ElasticSearch I'll take the node api status page as gospel. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:59am UTC](https://discuss.elastic.co/t/understanding-xms-xmx-options/4977/5 "2017-07-06T03:59:01Z")