X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;ds=sidebyside;f=HOWTO;h=ce1bd9e6131db987ea6c8992c5deeebd9bddc3bf;hb=48b35be009138ddca8d341f7767a1364400b6c06;hp=69b8cc6766850b6ceab07a0c15ea7e872142838e;hpb=2615cc4b28e7d0e436a625dff92e6a71ccc6c49b;p=fio.git

diff --git a/HOWTO b/HOWTO
index 69b8cc67..ce1bd9e6 100644
--- a/HOWTO
+++ b/HOWTO
@@ -354,11 +354,19 @@ use_os_rand=bool Fio can either use the random generator supplied by the OS
 		internal generator, which is often of better quality and
 		faster.
 
-fallocate=bool	By default, fio will use fallocate() to advise the system
-		of the size of the file we are going to write. This can be
-		turned off with fallocate=0. May not be available on all
-		supported platforms.  If using ZFS on Solaris this must be
-		set to 0 because ZFS doesn't support it.
+fallocate=str	Whether pre-allocation is performed when laying down files.
+		Accepted values are:
+
+			none		Do not pre-allocate space
+			posix		Pre-allocate via posix_fallocate()
+			keep		Pre-allocate via fallocate() with
+					FALLOC_FL_KEEP_SIZE set
+			0		Backward-compatible alias for 'none'
+			1		Backward-compatible alias for 'posix'
+
+		May not be available on all supported platforms. 'keep' is only
+		available on Linux.If using ZFS on Solaris this must be set to
+		'none' because ZFS doesn't support it. Default: 'posix'.
 
 fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
 		on what IO patterns it is likely to issue. Sometimes you
@@ -374,7 +382,10 @@ size=int	The total size of file io for this job. Fio will run until
 		fio will divide this size between the available files
 		specified by the job. If not set, fio will use the full
 		size of the given files or devices. If the the files
-		do not exist, size must be given.
+		do not exist, size must be given. It is also possible to
+		give size as a percentage between 1 and 100. If size=20%
+		is given, fio will use 20% of the full size of the given
+		files or devices.
 
 filesize=int	Individual file sizes. May be a range, in which case fio
 		will select sizes for files at random within the given range