X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=fio.1;h=c5c10af44ae6c3df8d17980bd3e2b883d5cc717a;hp=77773a0cb42db641fc1fd713b8a4130ba6b6a908;hb=38dad62d5154ffaad445bd0231b271b9a46a5190;hpb=5736c10dccc4124d99178b94e6759386420e5251 diff --git a/fio.1 b/fio.1 index 77773a0c..c5c10af4 100644 --- a/fio.1 +++ b/fio.1 @@ -172,11 +172,39 @@ Mixed sequential reads and writes. Mixed random reads and writes. .RE .P -For mixed I/O, the default split is 50/50. For random I/O, the number of I/Os -to perform before getting a new offset can be specified by appending -`:\fIint\fR' to the pattern type. The default is 1. +For mixed I/O, the default split is 50/50. For certain types of io the result +may still be skewed a bit, since the speed may be different. It is possible to +specify a number of IO's to do before getting a new offset, this is one by +appending a `:\fI\fR to the end of the string given. For a random read, it +would look like \fBrw=randread:8\fR for passing in an offset modifier with a +value of 8. See the \fBrw_sequencer\fR option. .RE .TP +.BI rw_sequencer \fR=\fPstr +If an offset modifier is given by appending a number to the \fBrw=\fR line, +then this option controls how that number modifies the IO offset being +generated. Accepted values are: +.RS +.RS +.TP +.B sequential +Generate sequential offset +.TP +.B identical +Generate the same offset +.RE +.P +\fBsequential\fR is only useful for random IO, where fio would normally +generate a new random offset for every IO. If you append eg 8 to randread, you +would get a new random offset for every 8 IO's. The result would be a seek for +only every 8 IO's, instead of for every IO. Use \fBrw=randread:8\fR to specify +that. As sequential IO is already sequential, setting \fBsequential\fR for that +would not result in any differences. \fBidentical\fR behaves in a similar +fashion, except it sends the same offset 8 number of times before generating a +new offset. +.RE +.P +.TP .BI kb_base \fR=\fPint The base unit for a kilobyte. The defacto base is 2^10, 1024. Storage manufacturers like to use 10^3 or 1000 as a base ten unit instead, for obvious