t/zbd: add test case to confirm no write with rwmixwrite=0 option

[fio.git] / HOWTO.rst

diff --git a/HOWTO.rst b/HOWTO.rst
index 6a8fb3e375b719c2c4e2f5effcef694763764495..847c035637226aaf32c2f6b37cfef37dc6c62b73 100644 (file)
--- a/HOWTO.rst
+++ b/HOWTO.rst
@@ -801,7 +801,7 @@ Target file/device
 
        On Windows, disk devices are accessed as :file:`\\\\.\\PhysicalDrive0` for
        the first device, :file:`\\\\.\\PhysicalDrive1` for the second etc.
-       Note: Windows and FreeBSD prevent write access to areas
+       Note: Windows and FreeBSD (refer to geom(4)) prevent write access to areas
        of the disk containing in-use data (e.g. filesystems).
 
        The filename "`-`" is a reserved name, meaning *stdin* or *stdout*.  Which
@@ -2507,6 +2507,10 @@ with the caveat that when used on the command line, they must come after the
        If this is set to 0, fio generates protection information for
        write case and verifies for read case. Default: 1.
 
+       For 16 bit CRC generation fio will use isa-l if available otherwise
+       it will use the default slower generator.
+       (see: https://github.com/intel/isa-l)
+
 .. option:: pi_chk=str[,str][,str] : [io_uring_cmd]
 
        Controls the protection information check. This can take one or more
@@ -3205,6 +3209,14 @@ I/O depth
 I/O rate
 ~~~~~~~~
 
+.. option:: thinkcycles=int
+
+       Stall the job for the specified number of cycles after an I/O has completed before
+       issuing the next. May be used to simulate processing being done by an application.
+       This is not taken into account for the time to be waited on for  :option:`thinktime`.
+       Might not have any effect on some platforms, this can be checked by trying a setting
+       a high enough amount of thinkcycles.
+
 .. option:: thinktime=time
 
        Stall the job for the specified period of time after an I/O has completed before issuing the
@@ -3956,9 +3968,11 @@ Measurements and reporting
 
 .. option:: per_job_logs=bool
 
-       If set, this generates bw/clat/iops log with per file private filenames. If
-       not set, jobs with identical names will share the log filename. Default:
-       true.
+        If set to true, fio generates bw/clat/iops logs with per job unique
+        filenames. If set to false, jobs with identical names will share a log
+        filename. Note that when this option is set to false log files will be
+        opened in append mode and if log files already exist the previous
+        contents will not be overwritten. Default: true.
 
 .. option:: group_reporting