Add blockalign/ba option

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 4e52e6509c18a6efb2350071d15b4899fb0be759..999f7778f37d9d9628f76189609411f7053e77b2 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -327,6 +327,14 @@ bs=int             The block size used for the io units. Defaults to 4k. Values
                can do so by passing an empty read size - bs=,8k will set
                8k for writes and leave the read default value.
 
+blockalign=int
+ba=int         At what boundary to align random IO offsets. Defaults to
+               the same as 'blocksize' the minimum blocksize given.
+               Minimum alignment is typically 512b for using direct IO,
+               though it usually depends on the hardware block size. This
+               option is mutually exclusive with using a random map for
+               files, so it will turn off that option.
+
 blocksize_range=irange
 bsrange=irange Instead of giving a single block size, specify a range
                and fio will mix the issued io block sizes. The issued