X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=e8fbd97f6ab2693920b93101e654873005516f3a;hp=68e17e9f4743b6738fe10c1e329be9783f8af746;hb=4f12432eee5bbd821a7baebd940c6890aafa703a;hpb=2b13e716c0921356c0930522718e00b8df34293a

diff --git a/HOWTO b/HOWTO
index 68e17e9f..e8fbd97f 100644
--- a/HOWTO
+++ b/HOWTO
@@ -378,7 +378,11 @@ filesize=int	Individual file sizes. May be a range, in which case fio
 fill_device=bool Sets size to something really large and waits for ENOSPC (no
 		space left on device) as the terminating condition. Only makes
                 sense with sequential write. For a read workload, the mount
-		point will be filled first then IO started on the result.
+		point will be filled first then IO started on the result. This
+		option doesn't make sense if operating on a raw device node,
+		since the size of that is already known by the file system.
+		Additionally, writing beyond end-of-device will not return
+		ENOSPC there.
 
 blocksize=int
 bs=int		The block size used for the io units. Defaults to 4k. Values