Add rw_sequencer option

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 190da4fa66f38af46a92f63a7ba0fc6c56c1b912..c5c10af44ae6c3df8d17980bd3e2b883d5cc717a 100644 (file)
--- 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<nr>\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=<str>\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
@@ -951,10 +979,13 @@ Disk utilization.
 .PD
 .SH TERSE OUTPUT
 If the \fB\-\-minimal\fR option is given, the results will be printed in a
-semicolon-delimited format suitable for scripted use.  The fields are:
+semicolon-delimited format suitable for scripted use.  Note that the first
+number in the line is the version number. If the output has to be changed
+for some reason, this number will be incremented by 1 to signify that
+change.  The fields are:
 .P
 .RS
-.B jobname, groupid, error
+.B version, jobname, groupid, error
 .P
 Read status:
 .RS
@@ -968,6 +999,10 @@ Completion latency:
 .RS
 .B min, max, mean, standard deviation
 .RE
+Total latency:
+.RS
+.B min, max, mean, standard deviation
+.RE
 Bandwidth:
 .RS
 .B min, max, aggregate percentage of total, mean, standard deviation
@@ -986,6 +1021,10 @@ Completion latency:
 .RS
 .B min, max, mean, standard deviation
 .RE
+Total latency:
+.RS
+.B min, max, mean, standard deviation
+.RE
 Bandwidth:
 .RS
 .B min, max, aggregate percentage of total, mean, standard deviation