filesetup: add native fallocate

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 37caa3c0ecd54a9371f483755ccb1f58dfdaf152..cf46349233f095bf5c786e4fed3bad5dc12ec8a3 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -853,10 +853,13 @@ Target file/device
                **pareto**
                        Use a *Pareto* distribution to decide what file to access.
 
-               **gauss**
+               **normal**
                        Use a *Gaussian* (normal) distribution to decide what file to
                        access.
 
+               **gauss**
+                       Alias for normal.
+
        For *random*, *roundrobin*, and *sequential*, a postfix can be appended to
        tell fio how many I/Os to issue before switching to a new file. For example,
        specifying ``file_service_type=random:8`` would cause fio to issue
@@ -1046,6 +1049,10 @@ I/O type
                **none**
                        Do not pre-allocate space.
 
+               **native**
+                       Use a platform's native pre-allocation call but fall back to
+                       **none** behavior if it fails/is not implemented.
+
                **posix**
                        Pre-allocate via :manpage:`posix_fallocate(3)`.
 
@@ -1060,8 +1067,9 @@ I/O type
                        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**.
+       on Linux. If using ZFS on Solaris this cannot be set to **posix**
+       because ZFS doesn't support pre-allocation. Default: **native** if any
+       pre-allocation methods are available, **none** if not.
 
 .. option:: fadvise_hint=str
 
@@ -1095,8 +1103,8 @@ I/O type
        offset will be used. Data before the given offset will not be touched. This
        effectively caps the file size at `real_size - offset`. Can be combined with
        :option:`size` to constrain the start and end range of the I/O workload.
-       A percentage can be specified by the percentage number plus 1 with preceding '-'.
-       For example, -1 is parsed as 0%, -10 is parsed as 9%, -101 is parsed as 100%.
+       A percentage can be specified by a number between 1 and 100 followed by '%',
+       for example, ``offset=20%`` to specify 20%.
 
 .. option:: offset_increment=int
 
@@ -1204,7 +1212,7 @@ I/O type
                **pareto**
                                Pareto distribution
 
-               **gauss**
+               **normal**
                                Normal (Gaussian) distribution
 
                **zoned**
@@ -1217,8 +1225,8 @@ I/O type
        values will yield in terms of hit rates.  If you wanted to use **zipf** with
        a `theta` of 1.2, you would use ``random_distribution=zipf:1.2`` as the
        option. If a non-uniform model is used, fio will disable use of the random
-       map. For the **gauss** distribution, a normal deviation is supplied as a
-       value between 0 and 100.
+       map. For the **normal** distribution, a normal (Gaussian) deviation is
+       supplied as a value between 0 and 100.
 
        For a **zoned** distribution, fio supports specifying percentages of I/O
        access that should fall within what range of the file or device. For