On Fri, 12 Mar 2010 10:40:58 +0000
John Robinson [off-list ref] wrote:

On 12/03/2010 03:39, Patrick J. LoPresti wrote:

quoted

From reading the documentation and source code, I gather "mdadm
--grow" is not supported for RAID-0 devices.

In my application, I am using md RAID-0 to stripe among several
(identical) hardware RAID-0 chassis.  I would like to extend my setup
by adding another chassis, but apparently, I cannot (?).

If I remember correctly, there were patches posted to this list recently 
to add support for reshaping RAID-0, and for migrating from RAID-0 to 
other RAID levels, but I don't remember whether they've made it in to 
the kernel/mdadm yet. I recommend a trawl through the last few months' 
archives.

I'll save you the effort.  No they haven't.

The current plan is to support reshaping RAID-0 but converting the
RAID0 to a degraded RAID4, then reshaping it, then converting back.

But the code isn't ready yet.

NeilBrown