Hook up the file hashing

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index ca095a322895be3065081db5bd600fb12609f3e7..d8c6b9414eef85be48779d7018682cf2bbd07470 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -344,6 +344,8 @@ ioengine=str        Defines how the job issues io to the file. The following
 
                        psync   Basic pread(2) or pwrite(2) io.
 
 
                        psync   Basic pread(2) or pwrite(2) io.
 

+                       vsync   Basic readv(2) or writev(2) IO.
+

                        libaio  Linux native asynchronous io.
 
                        posixaio glibc posix asynchronous io.
                        libaio  Linux native asynchronous io.
 
                        posixaio glibc posix asynchronous io.


@@ -381,7 +383,10 @@ ioengine=str       Defines how the job issues io to the file. The following
                                cycles according to the cpuload= and
                                cpucycle= options. Setting cpuload=85
                                will cause that job to do nothing but burn
                                cycles according to the cpuload= and
                                cpucycle= options. Setting cpuload=85
                                will cause that job to do nothing but burn

-                               85% of the CPU.
+                               85% of the CPU. In case of SMP machines,
+                               use numjobs=<no_of_cpu> to get desired CPU
+                               usage, as the cpuload only loads a single
+                               CPU at the desired rate.

 
                        guasi   The GUASI IO engine is the Generic Userspace
                                Asyncronous Syscall Interface approach
 
                        guasi   The GUASI IO engine is the Generic Userspace
                                Asyncronous Syscall Interface approach


@@ -402,8 +407,9 @@ iodepth=int This defines how many io units to keep in flight against
                concurrency.
 
 iodepth_batch=int This defines how many pieces of IO to submit at once.
                concurrency.
 
 iodepth_batch=int This defines how many pieces of IO to submit at once.

-               It defaults to the same as iodepth, but can be set lower
-               if one so desires.
+               It defaults to 1 which means that we submit each IO
+               as soon as it is available, but can be raised to submit
+               bigger batches of IO at the time.

 
 iodepth_low=int        The low water mark indicating when to start filling
                the queue again. Defaults to the same as iodepth, meaning
 
 iodepth_low=int        The low water mark indicating when to start filling
                the queue again. Defaults to the same as iodepth, meaning