Document validity of --assume-clean when all devices are zeroed.

>>
>> When I assemble an array I tend to have checked the devices before
>> hand; it would not be difficult to make the final pass a zeroing pass
>> if I knew I could vastly speed up post-assembly performance.  As I
>> stated, it's merely a lack of clarity in the documentation.
>
> If you would like to create a patch against the man page, I would be happy to
> accept it.
>
> NeilBrown

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/mdadm.8 b/mdadm.8
index f8f240a2ab1a0b8ed0f74238a2a2116c8e222a96..29e098b2083179abfa8f93840476f46de7ecc71d 100644 (file)
--- a/mdadm.8
+++ b/mdadm.8
@@ -648,6 +648,12 @@ data will be affected unless you actually write to the array.  It can
 also be used when creating a RAID1 or RAID10 if you want to avoid the
 initial resync, however this practice \(em while normally safe \(em is not
 recommended.  Use this only if you really know what you are doing.
+.IP
+When the devices that will be part of a new array were filled
+with zeros before creation the operator knows the array is
+actually clean. If that is the case, such as after running
+badblocks, this argument can be used to tell mdadm the
+facts the operator knows.
 
 .TP
 .BR \-\-backup\-file=