Oh that good to hear , i have one 128 Gb, couple of 512Gb and 1Tb disk installed on my R720 but not sure how to deal with the RAID config and suddenly installation got terminated.
I tried to disable it but it did not work or i might not aware how to do it correctly. I tried multiple setting but it didn’t worked for me atlast i tried making RAID 0 and installion moved aheada and stucked here.