I/O that completes. When writing to the disk log, that can quickly grow to a
very large size. Setting this option makes fio average the each log entry
over the specified period of time, reducing the resolution of the log. See
- :option:`log_max_value` as well. Defaults to 0, logging all entries.
+ :option:`log_window_value` as well. Defaults to 0, logging all entries.
Also see `Log File Formats`_.
.. option:: log_hist_msec=int
histogram logs contain 1216 latency bins. See :option:`write_hist_log`
and `Log File Formats`_.
-.. option:: log_max_value=bool
+.. option:: log_window_value=int, log_max_value=int
- If :option:`log_avg_msec` is set, fio logs the average over that window. If
- you instead want to log the maximum value, set this option to 1. Defaults to
- 0, meaning that averaged values are logged.
+ If :option:`log_avg_msec` is set, fio by default logs the average over that
+ window. This option determines whether fio logs the average, maximum or
+ both the values over the window. This only affects the latency logging,
+ as both average and maximum values for iops or bw log will be same.
+ Accepted values are:
+
+ **avg**
+ Log average value over the window. The default.
+
+ **max**
+ Log maximum value in the window.
+
+ **both**
+ Log both average and maximum value over the window.
+
+ **0**
+ Backward-compatible alias for **avg**.
+
+ **1**
+ Backward-compatible alias for **max**.
.. option:: log_offset=bool
by the ioengine specific :option:`cmdprio_percentage`.
Fio defaults to logging every individual I/O but when windowed logging is set
-through :option:`log_avg_msec`, either the average (by default) or the maximum
-(:option:`log_max_value` is set) *value* seen over the specified period of time
-is recorded. Each *data direction* seen within the window period will aggregate
-its values in a separate row. Further, when using windowed logging the *block
-size* and *offset* entries will always contain 0.
+through :option:`log_avg_msec`, either the average (by default), the maximum
+(:option:`log_window_value` is set to max) *value* seen over the specified period
+of time, or both the average *value* and maximum *value1* (:option:`log_window_value`
+is set to both) is recorded. The log file format when both the values are reported
+takes this form:
+
+ *time* (`msec`), *value*, *value1*, *data direction*, *block size* (`bytes`),
+ *offset* (`bytes`), *command priority*
+
+
+Each *data direction* seen within the window period will aggregate its values in a
+separate row. Further, when using windowed logging the *block size* and *offset*
+entries will always contain 0.
Client/Server
I/O that completes. When writing to the disk log, that can quickly grow to a
very large size. Setting this option makes fio average the each log entry
over the specified period of time, reducing the resolution of the log. See
-\fBlog_max_value\fR as well. Defaults to 0, logging all entries.
+\fBlog_window_value\fR as well. Defaults to 0, logging all entries.
Also see \fBLOG FILE FORMATS\fR section.
.TP
.BI log_hist_msec \fR=\fPint
in coarseness, fio outputs half as many bins. Defaults to 0, for which
histogram logs contain 1216 latency bins. See \fBLOG FILE FORMATS\fR section.
.TP
-.BI log_max_value \fR=\fPbool
-If \fBlog_avg_msec\fR is set, fio logs the average over that window. If
-you instead want to log the maximum value, set this option to 1. Defaults to
-0, meaning that averaged values are logged.
+.BI log_window_value \fR=\fPint "\fR,\fP log_max_value" \fR=\fPint
+If \fBlog_avg_msec\fR is set, fio by default logs the average over that window.
+This option determines whether fio logs the average, maximum or both the
+values over the window. This only affects the latency logging, as both average
+and maximum values for iops or bw log will be same. Accepted values are:
+.RS
+.TP
+.B avg
+Log average value over the window. The default.
+.TP
+.B max
+Log maximum value in the window.
+.TP
+.B both
+Log both average and maximum value over the window.
+.TP
+.B 0
+Backward-compatible alias for \fBavg\fR.
+.TP
+.B 1
+Backward-compatible alias for \fBmax\fR.
+.RE
.TP
.BI log_offset \fR=\fPbool
If this is set, the iolog options will include the byte offset for the I/O
(\fBprioclass\fR and \fBcmdprio_class\fR options).
.P
Fio defaults to logging every individual I/O but when windowed logging is set
-through \fBlog_avg_msec\fR, either the average (by default) or the maximum
-(\fBlog_max_value\fR is set) `value' seen over the specified period of time
-is recorded. Each `data direction' seen within the window period will aggregate
-its values in a separate row. Further, when using windowed logging the `block
-size' and `offset' entries will always contain 0.
+through \fBlog_avg_msec\fR, either the average (by default), the maximum
+(\fBlog_window_value\fR is set to max) `value' seen over the specified period of
+time, or both the average `value' and maximum `value1' (\fBlog_window_value\fR is
+set to both) is recorded. The log file format when both the values are reported
+takes this form:
+.RS
+.P
+time (msec), value, value1, data direction, block size (bytes), offset (bytes),
+command priority
+.RE
+.P
+Each `data direction' seen within the window period will aggregate its values
+in a separate row. Further, when using windowed logging the `block size' and
+`offset' entries will always contain 0.
.SH CLIENT / SERVER
Normally fio is invoked as a stand-alone application on the machine where the
I/O workload should be generated. However, the backend and frontend of fio can