add documentation about filename_format directory behavior

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index d3f957bf4db7ecdeab63bfc5f38bbbd8150881be..a1513e1259f7cc3001fb185a662150a9527dba34 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -795,6 +795,13 @@ Target file/device
        named :file:`testfiles.4`. The default of :file:`$jobname.$jobnum.$filenum`
        will be used if no other format specifier is given.
 
        named :file:`testfiles.4`. The default of :file:`$jobname.$jobnum.$filenum`
        will be used if no other format specifier is given.
 

+       If you specify a path then the directories will be created up to the
+       main directory for the file.  So for example if you specify
+       ``filename_format=a/b/c/$jobnum`` then the directories a/b/c will be
+       created before the file setup part of the job.  If you specify
+       :option:`directory` then the path will be relative that directory,
+       otherwise it is treated as the absolute path.
+

 .. option:: unique_filename=bool
 
        To avoid collisions between networked clients, fio defaults to prefixing any
 .. option:: unique_filename=bool
 
        To avoid collisions between networked clients, fio defaults to prefixing any