Add softrandommap and --alloc-size options

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index d8c6b9414eef85be48779d7018682cf2bbd07470..66ebebe8579dd5954e574bf016c31b5fbd0e5baf 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -219,6 +219,25 @@ filename=str       Fio normally makes up a filename based on the job name,
 opendir=str    Tell fio to recursively add any file it can find in this
                directory and down the file system tree.
 
+lockfile=str   Fio defaults to not doing any locking files before it does
+               IO to them. If a file or file descriptor is shared, fio
+               can serialize IO to that file to make the end result
+               consistent. This is usual for emulating real workloads that
+               share files. The lock modes are:
+
+                       none            No locking. The default.
+                       exclusive       Only one thread/process may do IO,
+                                       excluding all others.
+                       readwrite       Read-write locking on the file. Many
+                                       readers may access the file at the
+                                       same time, but writes get exclusive
+                                       access.
+
+               The option may be post-fixed with a lock batch number. If
+               set, then each thread/process may do that amount of IOs to
+               the file before giving up the lock. Since lock acqusition is
+               expensive, batching the lock/unlocks will speed up IO.
+
 readwrite=str
 rw=str         Type of io pattern. Accepted values are:
 
@@ -463,6 +482,12 @@ norandommap        Normally fio will cover every block of the file when doing
                fio doesn't track potential block rewrites which may alter
                the calculated checksum for that block.
 
+softrandommap  See norandommap. If fio runs with the random block map enabled
+               and it fails to allocate the map, if this option is set it
+               will continue without a random block map. As coverage will
+               not be as complete as with random maps, this option is
+               disabled by default.
+
 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