Hi,

> Command mkfs.ext4 -L boot /dev/md0 had exit code 1
> Executing: parted -s /dev/sdd set 2 raid on
> Command parted -s /dev/sdd set 2 raid on had exit code 1
> Executing: parted -s /dev/sdc set 2 raid on
> Command parted -s /dev/sdc set 2 raid on had exit code 1
> Executing: parted -s /dev/sdb set 2 raid on
> Command parted -s /dev/sdb set 2 raid on had exit code 1
> Executing: parted -s /dev/sda set 2 raid on
> Command parted -s /dev/sda set 2 raid on had exit code 1

I think you encounter following bug: 
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=583910
Hopefully it will be fixed soon.

Best regards,
Manuel Hachtkemper

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