$ sudo mdadm --create --verbose /dev/md0 --level=0 --raid-devices=2 /dev/vda /dev/vdb
mdadm: array /dev/md0 started.
$ sudo ros install -d /dev/md0
The file /host/dev/md01 does not exist and no size was specified.
$ ls /host/dev | grep md
md0
md0p1
Where did he get this device: md01 ??