[PATCH] md: allow md array component size to be accessed and set via sysfs
Signed-off-by: Neil Brown <neilb@suse.de>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/Documentation/md.txt b/Documentation/md.txt
index 9710138..0a2e10a 100644
--- a/Documentation/md.txt
+++ b/Documentation/md.txt
@@ -174,6 +174,15 @@
The size should be atleast PAGE_SIZE (4k) and should be a power
of 2. This can only be set while assembling an array
+ component_size
+ For arrays with data redundancy (i.e. not raid0, linear, faulty,
+ multipath), all components must be the same size - or at least
+ there must a size that they all provide space for. This is a key
+ part or the geometry of the array. It is measured in sectors
+ and can be read from here. Writing to this value may resize
+ the array if the personality supports it (raid1, raid5, raid6),
+ and if the component drives are large enough.
+
As component devices are added to an md array, they appear in the 'md'
directory as new directories named
dev-XXX