GUASI API change

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 051a4554a95ff8a1229d3154a1c6bd31f701c9c6..7cab05379f612034abdc173f03acb8d7850f902f 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -240,6 +240,13 @@ rw=str             Type of io pattern. Accepted values are:
 randrepeat=bool        For random IO workloads, seed the generator in a predictable
                way so that results are repeatable across repetitions.
 
+fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
+               on what IO patterns it is likely to issue. Sometimes you
+               want to test specific IO patterns without telling the
+               kernel about it, in which case you can disable this option.
+               If set, fio will use POSIX_FADV_SEQUENTIAL for sequential
+               IO and POSIX_FADV_RANDOM for random IO.
+
 size=siint     The total size of file io for this job. This may describe
                the size of the single file the job uses, or it may be
                divided between the number of files in the job. If the
@@ -548,10 +555,22 @@ verify=str        If writing to a file, fio can verify the file contents
                        crc32   Use a crc32 sum of the data area and store
                                it in the header of each block.
 
+                       null    Only pretend to verify. Useful for testing
+                               internals with ioengine=null, not for much
+                               else.
+
                This option can be used for repeated burn-in tests of a
                system to make sure that the written data is also
                correctly read back.
 
+verifysort=bool        If set, fio will sort written verify blocks when it deems
+               it faster to read them back in a sorted manner. This is
+               often the case when overwriting an existing file, since
+               the blocks are already laid out in the file system. You
+               can ignore this option unless doing huge amounts of really
+               fast IO where the red-black tree sorting CPU time becomes
+               significant.
+               
 stonewall      Wait for preceeding jobs in the job file to exit, before
                starting this one. Can be used to insert serialization
                points in the job file. A stone wall also implies starting