# Some questions on system.diskio latency metrics **URL:** \ **Category:** Metrics\ **Created:** [March 2, 2023, 3:19am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817 "2023-03-02T03:19:24Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![CatLoveFishma](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/catlovefishma/32/113704_2.png) [@CatLoveFishma](https://discuss.elastic.co/u/CatLoveFishma)\ **Post date:** [March 2, 2023, 3:19am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817/1 "2023-03-02T03:19:24Z")
Hello, I am trying to get a better understanding of the disk io metrics below. Included are the definitions for each per the Elastic documentation online. system.diskio.read.time - total number of milliseconds spent by all reads system.diskio.write.time - total number of milliseconds spent by all writes system.diskio.write.time - The total number of of milliseconds spent doing I/Os. system.diskio.read.bytes - The total number of bytes read successfully system.diskio.write.bytes - The total number of bytes write successfully system.diskio.read.count - The total number of reads completed successfully. system.diskio.write.count - The total number of writes completed successfully. Q1: In the definitions of system.diskio.read/write.time, the total number of milliseconds spent by all reads/writes.I found that the total time is very large, far greater than the sampling period I set. SO, what time does this total time consist of？ Q2：Similar to Q1，what bytes does this total bytes consist of？ Q3: Does system.diskio.write.read/count record all read/write operations in the event.duration time？ ---
**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\ **Post date:** [March 2, 2023, 5:02am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817/2 "2023-03-02T05:02:01Z")
These metrics are counters. This is how they recorded on OSs That means they a monotonically increasing numbers. Counter A counter is a cumulative metric that represents a single monotonically increasing counter whose value can only increase or be reset to zero on restart. For example, you can use a counter to represent the number of requests served, tasks completed, or errors. So to calculate the write time per bucket / time range write.time(1) - write.time(0) That is the total ms spent on writes during that time span. Look closely you probably will want to look at them by `system.filesystem.device_name` And to calculate the like read/write MB/s So to visualize them in Lens use the function counter rate. So to calculate a rate it is a derivative.... (write.bytes(1) - write.bytes(0))/time bucket span Look closely you probably will want to look at them by `system.filesystem.device_name` Can also look at the OOTB dashboard and visualizations to see.. ---
**Author:** ![CatLoveFishma](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/catlovefishma/32/113704_2.png) [@CatLoveFishma](https://discuss.elastic.co/u/CatLoveFishma)\ **Post date:** [March 2, 2023, 6:47am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817/3 "2023-03-02T06:47:56Z")
Thank you. But I still have a question. Displayed in the metricbeat document, **disk contains disk IO metrics collected from the operating system.** So,does Linux have commands that can obtain similar data？ ---
**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\ **Post date:** [March 2, 2023, 7:00am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817/4 "2023-03-02T07:00:31Z")
Well that is a bit outside elasticsearch topics.... You can look it up on Google > **[How to Monitor Disk IO in a Linux System | Baeldung on Linux](https://www.baeldung.com/linux/monitor-disk-io)** > > In this tutorial, we'll discuss how to monitor disk I/O activity in the Linux system. > You can also look at the metricbeat code if you like ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [March 30, 2023, 7:00am UTC](https://discuss.elastic.co/t/some-questions-on-system-diskio-latency-metrics/326817/5 "2023-03-30T07:00:59Z")
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