X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=95d059e766e6399f29d8097331a076db4df29161;hp=1b34c283af0f385e00407a9167c6ec02820ad4a1;hb=71619dc28506f7b7b40905b942e992b02f0d5b96;hpb=8aeebd5570ac4fccbcdd48f2e6f1cf1577f3c08d diff --git a/HOWTO b/HOWTO index 1b34c283..95d059e7 100644 --- a/HOWTO +++ b/HOWTO @@ -179,7 +179,10 @@ siint SI integer. A whole number value, which may contain a postfix bool Boolean. Usually parsed as an integer, however only defined for true and false (1 and 0). irange Integer range with postfix. Allows value range to be given, such - as 1024-4096. Also see siint. + as 1024-4096. A colon may also be used as the seperator, eg + 1k:4k. If the option allows two sets of ranges, they can be + specified with a ',' or '/' delimiter: 1k-4k/8k-32k. Also see + siint. With the above in mind, here follows the complete list of fio job parameters. @@ -211,6 +214,9 @@ rw=str Type of io pattern. Accepted values are: For certain types of io the result may still be skewed a bit, since the speed may be different. +randrepeat=bool For random IO workloads, seed the generator in a predictable + way so that results are repeatable across repetitions. + size=siint The total size of file io for this job. This may describe the size of the single file the job uses, or it may be divided between the number of files in the job. If the @@ -274,7 +280,10 @@ iodepth=int This defines how many io units to keep in flight against concurrency. direct=bool If value is true, use non-buffered io. This is usually - O_DIRECT. Defaults to true. + O_DIRECT. + +buffered=bool If value is true, use buffered io. This is the opposite + of the 'direct' option. Defaults to true. offset=siint Start io at the given offset in the file. The data before the given offset will not be touched. This effectively @@ -344,7 +353,7 @@ startdelay=int Start this job the specified number of seconds after fio jobs, and you want to delay starting some jobs to a certain time. -timeout=int Tell fio to terminate processing after the specified number +runtime=int Tell fio to terminate processing after the specified number of seconds. It can be quite hard to determine for how long a specified job will run, so this parameter is handy to cap the total runtime to a given time. @@ -494,7 +503,7 @@ cpuchunks=int If the job is a CPU cycle eater, split the load into fio spits out a lot of output. While running, fio will display the status of the jobs created. An example of that would be: -Threads running: 1: [_r] [24.79% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s] +Threads: 1: [_r] [24.8% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s] The characters inside the square brackets denote the current status of each thread. The possible values (in typical life cycle order) are: @@ -526,10 +535,11 @@ direction, the output looks like: Client1 (g=0): err= 0: write: io= 32MiB, bw= 666KiB/s, runt= 50320msec - slat (msec): min= 0, max= 136, avg= 0.03, dev= 1.92 - clat (msec): min= 0, max= 631, avg=48.50, dev=86.82 - bw (KiB/s) : min= 0, max= 1196, per=51.00%, avg=664.02, dev=681.68 + slat (msec): min= 0, max= 136, avg= 0.03, stdev= 1.92 + clat (msec): min= 0, max= 631, avg=48.50, stdev=86.82 + bw (KiB/s) : min= 0, max= 1196, per=51.00%, avg=664.02, stdev=681.68 cpu : usr=1.49%, sys=0.25%, ctx=7969 + IO depths : 1=0.1%, 2=0.3%, 4=0.5%, 8=99.0%, 16=0.0%, 32=0.0%, >32=0.0% The client number is printed, along with the group id and error of that thread. Below is the io statistics, here for writes. In the order listed, @@ -554,6 +564,11 @@ runt= The runtime of that thread same disk, since they are then competing for disk access. cpu= CPU usage. User and system time, along with the number of context switches this thread went through. +IO depths= The distribution of io depths over the job life time. The + numbers are divided into powers of 2, so for example the + 16= entries includes depths up to that value but higher + than the previous entry. In other words, it covers the + range from 16 to 31. After each client has been listed, the group statistics are printed. They will look like this: