Posted 1st August 2015 on andypeace.com.
fio, the flexible IO tester, is a very useful tool for benchmarking IO performance. It has an option to produce minimal output, which is very useful when gathering data for later processing, e.g. graphing. The man page for fio describes the output format, but does not number the fields. This means that when extracting fields, one must count the fields in the man page to find the correct index to extract.
This page provides a handy reference to the field indexes used in the output to hopefully save you some time and effort.
| Field | Description |
|---|---|
| 1 | terse version |
| 2 | fio version |
| 3 | jobname |
| 4 | groupid |
| 5 | error |
| Read status: | |
| 6 | Total I/O (KB) |
| 7 | bandwidth (KB/s) |
| 8 | IOPS |
| 9 | runtime (ms) |
| Submission latency: | |
| 10 | min |
| 11 | max |
| 12 | mean |
| 13 | standard deviation |
| Completion latency: | |
| 14 | min |
| 15 | max |
| 16 | mean |
| 17 | standard deviation |
| Completion latency percentiles (20 fields): | |
| 18-37 | Xth percentile=usec |
| Total latency: | |
| 38 | min |
| 39 | max |
| 40 | mean |
| 41 | standard deviation |
| Bandwidth: | |
| 42 | min |
| 43 | max |
| 44 | aggregate percentage of total |
| 45 | mean |
| 46 | standard deviation |
| Write status: | |
| 47 | Total I/O (KB) |
| 48 | bandwidth (KB/s) |
| 49 | IOPS |
| 50 | runtime (ms) |
| Submission latency: | |
| 51 | min |
| 52 | max |
| 53 | mean |
| 54 | standard deviation |
| Completion latency: | |
| 55 | min |
| 56 | max |
| 57 | mean |
| 58 | standard deviation |
| Completion latency percentiles (20 fields): | |
| 59-78 | Xth percentile=usec |
| Total latency: | |
| 79 | min |
| 80 | max |
| 81 | mean |
| 82 | standard deviation |
| Bandwidth: | |
| 83 | min |
| 84 | max |
| 85 | aggregate percentage of total |
| 86 | mean |
| 87 | standard deviation |
| CPU usage: | |
| 88 | user |
| 89 | system |
| 90 | context switches |
| 91 | major page faults |
| 92 | minor page faults |
| IO depth distribution: | |
| 93 | <=1 |
| 94 | 2 |
| 95 | 4 |
| 96 | 8 |
| 97 | 16 |
| 98 | 32 |
| 99 | >=64 |
| IO latency distribution (microseconds): | |
| 100 | <=2 |
| 101 | 4 |
| 102 | 10 |
| 103 | 20 |
| 104 | 50 |
| 105 | 100 |
| 106 | 250 |
| 107 | 500 |
| 108 | 750 |
| 109 | 1000 |
| IO latency distribution (milliseconds): | |
| 110 | <=2 |
| 111 | 4 |
| 112 | 10 |
| 113 | 20 |
| 114 | 50 |
| 115 | 100 |
| 116 | 250 |
| 117 | 500 |
| 118 | 750 |
| 118 | 1000 |
| 120 | 2000 |
| 121 | >=2000 |
| Disk utilization (1 for each disk used, for disk n, n is zero-based): | |
| 122+10n | name |
| 123+10n | read ios |
| 124+10n | write ios |
| 125+10n | read merges |
| 126+10n | write merges |
| 127+10n | read ticks |
| 128+10n | write ticks |
| 129+10n | read in-queue time |
| 130+10n | write in-queue time |
| 131+10n | disk utilization |
| 132+10n | percentage |
| Error Info (dependent on continue_on_error, default off): | |
| F-1 | total # errors |
| F-0 | first error code |
| newline | text description (if provided in config - appears on newline) |