Mention default values for readwrite=/ioengine=/mem= in documentation

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 1d4e46c7ec95ed4990b591a2d4dc7f9c968e72b0..ca1542d5fdf88b7fa0e6e607ab019a98c5d2d770 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -329,18 +329,15 @@ directory=str     Prefix filenames with this directory. Used to place files
 filename=str   Fio normally makes up a filename based on the job name,
                thread number, and file number. If you want to share
                files between threads in a job or several jobs, specify
 filename=str   Fio normally makes up a filename based on the job name,
                thread number, and file number. If you want to share
                files between threads in a job or several jobs, specify

-               a filename for each of them to override the default. If
-               the ioengine used is 'net', the filename is the host, port,
-               and protocol to use in the format of =host,port,protocol.
-               See ioengine=net for more. If the ioengine is file based, you
-               can specify a number of files by separating the names with a
-               ':' colon. So if you wanted a job to open /dev/sda and /dev/sdb
-               as the two working files, you would use
-               filename=/dev/sda:/dev/sdb. On Windows, disk devices are
-               accessed as \\.\PhysicalDrive0 for the first device,
-               \\.\PhysicalDrive1 for the second etc. Note: Windows and
-               FreeBSD prevent write access to areas of the disk containing
-               in-use data (e.g. filesystems).
+               a filename for each of them to override the default.
+               If the ioengine is file based, you can specify a number of
+               files by separating the names with a ':' colon. So if you
+               wanted a job to open /dev/sda and /dev/sdb as the two working
+               files, you would use filename=/dev/sda:/dev/sdb. On Windows,
+               disk devices are accessed as \\.\PhysicalDrive0 for the first
+               device, \\.\PhysicalDrive1 for the second etc. Note: Windows
+               and FreeBSD prevent write access to areas of the disk
+               containing in-use data (e.g. filesystems).

                If the wanted filename does need to include a colon, then
                escape that with a '\' character. For instance, if the filename
                is "/dev/dsk/foo@3,0:c", then you would use
                If the wanted filename does need to include a colon, then
                escape that with a '\' character. For instance, if the filename
                is "/dev/dsk/foo@3,0:c", then you would use


@@ -408,6 +405,7 @@ rw=str              Type of io pattern. Accepted values are:
                        trimwrite       Mixed trims and writes. Blocks will be
                                        trimmed first, then written to.
 
                        trimwrite       Mixed trims and writes. Blocks will be
                                        trimmed first, then written to.
 

+               Fio defaults to read if the option is not specified.

                For the mixed io types, the default is to split them 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
                For the mixed io types, the default is to split them 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


@@ -702,13 +700,14 @@ ioengine=str      Defines how the job issues io to the file. The following
                        sync    Basic read(2) or write(2) io. lseek(2) is
                                used to position the io location.
 
                        sync    Basic read(2) or write(2) io. lseek(2) is
                                used to position the io location.
 

-                       psync   Basic pread(2) or pwrite(2) io.
+                       psync   Basic pread(2) or pwrite(2) io. Default on all
+                               supported operating systems except for Windows.

 
                        vsync   Basic readv(2) or writev(2) IO.
 
                        pvsync  Basic preadv(2) or pwritev(2) IO.
 
 
                        vsync   Basic readv(2) or writev(2) IO.
 
                        pvsync  Basic preadv(2) or pwritev(2) IO.
 

-                       psync2  Basic preadv2(2) or pwritev2(2) IO.
+                       pvsync2 Basic preadv2(2) or pwritev2(2) IO.

 
                        libaio  Linux native asynchronous io. Note that Linux
                                may only support queued behaviour with
 
                        libaio  Linux native asynchronous io. Note that Linux
                                may only support queued behaviour with


@@ -720,6 +719,7 @@ ioengine=str        Defines how the job issues io to the file. The following
                        solarisaio Solaris native asynchronous io.
 
                        windowsaio Windows native asynchronous io.
                        solarisaio Solaris native asynchronous io.
 
                        windowsaio Windows native asynchronous io.

+                               Default on Windows.

 
                        mmap    File is memory mapped and data copied
                                to/from using memcpy(3).
 
                        mmap    File is memory mapped and data copied
                                to/from using memcpy(3).


@@ -752,7 +752,7 @@ ioengine=str        Defines how the job issues io to the file. The following
 
                        cpuio   Doesn't transfer any data, but burns CPU
                                cycles according to the cpuload= and
 
                        cpuio   Doesn't transfer any data, but burns CPU
                                cycles according to the cpuload= and

-                               cpucycle= options. Setting cpuload=85
+                               cpuchunks= options. Setting cpuload=85

                                will cause that job to do nothing but burn
                                85% of the CPU. In case of SMP machines,
                                use numjobs=<no_of_cpu> to get desired CPU
                                will cause that job to do nothing but burn
                                85% of the CPU. In case of SMP machines,
                                use numjobs=<no_of_cpu> to get desired CPU


@@ -1067,7 +1067,8 @@ nice=int  Run the job with the given nice value. See man nice(2).
 
 prio=int       Set the io priority value of this job. Linux limits us to
                a positive value between 0 and 7, with 0 being the highest.
 
 prio=int       Set the io priority value of this job. Linux limits us to
                a positive value between 0 and 7, with 0 being the highest.

-               See man ionice(1).
+               See man ionice(1). Refer to an appropriate manpage for
+               other operating systems since meaning of priority may differ.

 
 prioclass=int  Set the io priority class. See man ionice(1).
 
 
 prioclass=int  Set the io priority class. See man ionice(1).
 


@@ -1223,6 +1224,7 @@ mem=str           Fio can use various types of memory as the io unit buffer.
                The allowed values are:
 
                        malloc  Use memory from malloc(3) as the buffers.
                The allowed values are:
 
                        malloc  Use memory from malloc(3) as the buffers.

+                               Default memory type.

 
                        shm     Use shared memory as the buffers. Allocated
                                through shmget(2).
 
                        shm     Use shared memory as the buffers. Allocated
                                through shmget(2).