On 26 November 2013 18:07, David F. [off-list ref] wrote:

As a workaround to the mdadm issue with the spare drive we were going
to have them activate DMRAID but that ends up with the information
below.  Specifically something about dm-raid45 but we had to drop that
because it no longer compiles in the latest kernels and we couldn't
find an update that would.   Any ideas?  (still working on getting the
dump - the fact that tmpfs doesn't support sparse files makes having
the customer create the dump via a script we provide a bit more
involved):

Ubuntu kernels still somewhat maintain and have dm-raid-45 module.

Install linux-image-extra-virtual package which will pull in correct
versioned packaged with extra modules.

It is planned however to migrate off & drop dm-raid-45 module soon.

ps. latest version I can find is
3.8.0-22-generic/kernel/ubuntu/dm-raid4-5/dm-raid45.ko

Regards,

Dmitrijs.