Error installing DMRaid

[rolyreefer]

I am trying to install Ubunto alternative on my computer which has 2 raid 0 disks. I have installed DMRaid, as per the instructions on this site, but it comes withh this error message:

sudo dmraid -ay
ERROR: isw device for volume "ARRAY" broken on /dev/sdb in RAID set "isw_dajfdafdfi_ARRAY"
ERROR: isw: wrong # of devices in RAID set "isw_dajfdafdfi_ARRAY" [1/2] on /dev/sdb
RAID set "isw_dajfdafdfi_ARRAY" was not activated

Please can anyone help.

Thanks