On Saturday 22 August 2009 02:34:12 NeilBrown wrote:

You say md0 is raid1 but mdstat shows it to be raid10, so that won't boot.

Thanks Neil.  However that was an early attempt before I knew RAID10 won't boot.

'raid autodetect' only works for 0.90 metadata, and you are using 1.x.
You should not use 'raid autodetect' partitions.  Rather the initrd
should use mdadm to assemble the arrays.  Most distros seem to get this
right these days.  Maybe you just need to rebuild your
initrd...

I am not using an initrd.  Have all the RAID and disk drivers built into the (custom-compiled) kernel.  It uses mdadm to assemble the arrays?  Maybe this is the problem.

I am using this procedure to build a RAID array from a live system:
http://www.howtoforge.com/software-raid1-grub-boot-debian-etch

It is very lucid and clear, however I am slightly modifying it to use RAID10 on my second and third partitions.  When I come to 
update-initramfs -u
... the only initrd it updates is for an old stock kernel.  It doesn't build one for any of my compiled kernels.

What partition type should I use rather than raid autodetect?  Or should I revert to 0.90 metadata?

Looking at dmesg it does say that md1 & 2 do not have a valid ==v.90== superblock.  There is no other linux raid partition type, so I guess it's got to be v.090.  Why do they make 1.1 and 1.2 then, if they do not work?