Add ability to invoke fallocate() FALLOC_FL_KEEP_SIZE.

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 0ced604de4f82b0fadb7345b34e61735d46a0b01..ad5040b37372e93415b7783db9924934211213cf 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -220,10 +220,32 @@ offsets, or it can use it's own internal generator (based on Tausworthe).
 Default is to use the internal generator, which is often of better quality and
 faster. Default: false.
 .TP
-.BI fallocate \fR=\fPbool
-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.
+.BI fallocate \fR=\fPstr
+Whether pre-allocation is performed when laying down files. Accepted values
+are:
+.RS
+.RS
+.TP
+.B none
+Do not pre-allocate space.
+.TP
+.B posix
+Pre-allocate via posix_fallocate().
+.TP
+.B keep
+Pre-allocate via fallocate() with FALLOC_FL_KEEP_SIZE set.
+.TP
+.B 0
+Backward-compatible alias for 'none'.
+.TP
+.B 1
+Backward-compatible alias for 'posix'.
+.RE
+.P
+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'.
+.RE
 .TP
 .BI fadvise_hint \fR=\fPbool
 Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns