# Elasticsearch indexing performance io wait **URL:** \ **Category:** Elasticsearch\ **Created:** [October 1, 2018, 4:55pm UTC](https://discuss.elastic.co/t/elasticsearch-indexing-performance-io-wait/150587 "2018-10-01T16:55:01Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![matw](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/matw/32/13913_2.png) [@matw](https://discuss.elastic.co/u/matw)\ **Post date:** [October 1, 2018, 4:55pm UTC](https://discuss.elastic.co/t/elasticsearch-indexing-performance-io-wait/150587/1 "2018-10-01T16:55:01Z")
I've got 2 similar deployments of our application: 5.6.1 elasticsearch, soon to be upgraded VM virtualisation 8 CPU (Intel(R) Xeon(R) CPU E5-2640 0 @ 2.50GHz) 12 Gigs of RAM assigned No SSD i've got very different indexing rate on both machines, with the same data to index. the fast machine needs about **0.2 ms** to index one document, the slow one **0.9ms** , and has usually a very high load. i think it's an issue of the Virtualisation but **i just want to rule out, that it's the hard disk**. So on both machines, top shows me wa(it) usually 0, sometimes up to 2. I think it's not a harddrive issue. if it would be i'd expect much higher waits. Or am I wrong? i calculate the time needed to index 1 doc by stats: node.indices.indexing.index\_time\_in\_millis / node.indices.indexing.index\_total iostat sample ``` iostat 5 Linux 3.10.0-693.2.2.el7.centos.plus.x86_64 (tracer2) 2018-10-02 _x86_64_ (8 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 35,51 22,29 2,01 0,22 0,00 39,96 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 181,99 125,30 11490,17 129009633 11830256952 avg-cpu: %user %nice %system %iowait %steal %idle 43,15 50,56 2,83 0,30 0,00 3,16 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 322,60 0,00 14434,40 0 72172 avg-cpu: %user %nice %system %iowait %steal %idle 52,43 41,70 2,73 0,03 0,00 3,11 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 283,40 0,00 5685,60 0 28428 avg-cpu: %user %nice %system %iowait %steal %idle 52,77 43,05 2,36 0,03 0,00 1,80 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 320,40 0,00 31557,60 0 157788 avg-cpu: %user %nice %system %iowait %steal %idle 49,03 44,37 2,41 0,40 0,00 3,79 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 298,00 0,00 7840,80 0 39204 avg-cpu: %user %nice %system %iowait %steal %idle 50,03 45,94 2,20 0,03 0,00 1,80 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 316,80 0,00 15043,20 0 75216 avg-cpu: %user %nice %system %iowait %steal %idle 50,66 44,10 2,53 0,03 0,00 2,68 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn sda 275,60 0,00 8480,80 0 42404 ``` can i rule out the Harddisk as reason for this slow index speed? thanks! ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [October 29, 2018, 4:55pm UTC](https://discuss.elastic.co/t/elasticsearch-indexing-performance-io-wait/150587/2 "2018-10-29T16:55:03Z")
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