Re: converting RAID5 to RAID10

On Thursday October 5, ask@develooper.com wrote:

On Oct 5, 2006, at 3:15 AM, Jurriaan Kalkman wrote:

quoted

AFAIK, linux raid-10 is not exactly raid 1+0, it allows you to, for
example, use 3 disks.

I made a raid-10 device earlier today with 7 drives and I was  
surprised to see that it reported to use all of them.  I thought it'd  
make one of them a spare (or complain about the odd number of drives).

How does that work?  (Or is it the "number of drives reported" bug  
Neil referred to a moment ago?  I use FC6's version of 2.6.18).

If you wanted 6 drives and a spare you need to ask for in: -n6 -x1.
If you asked for 7 drives in a raid10 you get them.
The data is laid out thus:

   A A B B C C D
   D E E F F G G
   H H I I J J K
   K L L M M N N
(each column in a drive, each letter is a chunk of data).

NeilBrown