question about RAID10 near and far layouts

[plug bert <plugbert@yahoo.com>]

hi peeps,

i've been reading through

http://en.wikipedia.org/wiki/Non-standard_RAID_levels

and just wanted to verify if my understanding is correct.

Is "near" safer than "far"?

e.g. given 4 drives in RAID10 array, n2:

4 drives

1 2 3 4
--------------
A1 A1 A2 A2
A3 A3 A4 A4
A5 A5 A6 A6
A7 A7 A8 A8

you'd lose the array if either 1&2 or 3&4 goes down at the same time.


With 4 drives in RAID10 array, f2:

4 drives
1 2 3 4
--------------------
A1 A2 A3 A4
A5 A6 A7 A8
A9 A10 A11 A12
.. .. .. ..
A4 A1 A2 A3
A8 A5 A6 A7
A12 A9 A10 A11

...there seems to be a lot more combinations that can result in a trashed array(1&2, 2&3, 3&4).

Is my analysis correct? Inputs are more than welcome, tia