# Recommended File System Settings for Elasticsearch **URL:** \ **Category:** Elasticsearch\ **Created:** [July 18, 2014, 10:20am UTC](https://discuss.elastic.co/t/recommended-file-system-settings-for-elasticsearch/18733 "2014-07-18T10:20:07Z")\ **Posts on this page:** 1\ **Showing post:** 4
**Author:** ![jprante](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/jprante/32/44941_2.png) [@jprante](https://discuss.elastic.co/u/jprante)\ **Post date:** [July 18, 2014, 2:03pm UTC](https://discuss.elastic.co/t/recommended-file-system-settings-for-elasticsearch/18733/4 "2014-07-18T14:03:31Z")
Elasticsearch does not set the read/write in 4k blocks, this is up to the JVM/OS. Elastisearch uses Lucene and Lucene wraps all reads and write into Java I/O streams, where Java uses the OS layer, and the OS uses the file system drivers. There are some rule of thumb: most important, don't mess with the block size. Because the virtual memory page size of Linux is 4k, and reading/writing pages from devices to memory should be fast, you will often find 4k blocksize and a factor of 4k for buffers of random access workload pattern. The Linux distributions come with good defaults. There is also readahead buffering on fs driver layer for fast reads but these values strongly depend on the filesystem and drive type. You can try if ES loads Lucene indices files much faster if you increase the readahead buffering of the fs but I doubt it. Try with tools like dd to get an impression of how fast your file system works. Elasticsearch/Lucene always appends data to the index like a log device. There are no in-place updates. Old files are dropped after being copied to new files. Today the main choice is between SSDs and disk spindle drives. SSDs are preferred because of the high IOPS numbers and bulk transfer rates, this reduces the IO system load significantly. Most important setting is RAID and the noatime parameter on fs mount to disable file access modification time writing. This saves a lot of unnecessary seeks and writes on spindle drives. Best performance for Elasticsearch searches is dependent on RAM, not on disks. The more RAM you have, the more files the OS is caching. To set up mmapfs and give enough fs cache to Elasticsearch is one of the keys to search performance. Jörg On Fri, Jul 18, 2014 at 12:20 PM, horst knete [baduncle23@hotmail.de](mailto:baduncle23@hotmail.de) wrote: > Hey Guys, > > we are going to expand our development ES-System to an productive > environment and we got fresh new storage which waits to be formatted. > > In order to get the best performance for elasticsearch, we´d like to know > what the recommended settings are. > > Does elasticsearch reads/writes in a sequential way or are there much > random access on the indices? > > Which block-size would you recommend? ( i´ve heard elasticsearch > reads/writes in 4k blocks, right? ) > > Thanks for response > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/8181f3db-1ac7-4c32-aece-169687eb538c%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/8181f3db-1ac7-4c32-aece-169687eb538c%40googlegroups.com) > [https://groups.google.com/d/msgid/elasticsearch/8181f3db-1ac7-4c32-aece-169687eb538c%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/8181f3db-1ac7-4c32-aece-169687eb538c%40googlegroups.com?utm_medium=email&utm_source=footer) > . > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAKdsXoHTr%2BtASS-nXj%3DDfRaV8qSqPnieVMFdjJJjcJc40B-1bQ%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAKdsXoHTr%2BtASS-nXj%3DDfRaV8qSqPnieVMFdjJJjcJc40B-1bQ%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). --- _[View the full topic](https://discuss.elastic.co/t/recommended-file-system-settings-for-elasticsearch/18733)._