Was: [RFC PATCH 2.6.23.1] md: add dm-raid1 read balancing

Konstantin Sharlaimov [off-list ref] writes:

This patch adds RAID1 read balancing to device mapper. A read operation
that is close (in terms of sectors) to a previous read or write goes to 
the same mirror.

I wonder if there shouldn't be a way to turn this off (or if there
already is one).

Or more generaly an option to say what is "near". Specifically I would
like to teach the raid1 layer that I have 2 external raid boxes with a
16k chunk size. So read/write within a 16k chunk will be the same disk
but the next 16k are a different disk and "near" doesn't apply
anymore.

MfG
        Goswin