For the 2 1TB drives you might have to use the software raid in the DSS to let them sync back up unless they where deleted from the Console and if so then the data is gone if not then try to use the DSS in the SW RAID to let them connect again unless there are other issues. Log could provide more information but if you have DSS Lite you will need to purchase a support plan from the link below in order to gain support for a free product.
if volume group is missing, can I get it back, repair it or something?
Is there some recovery software what I can use to scan my drives and restore my files?
what file system DSS uses?
If you used the "Delete contents of Unit" in the Extended tools then the data is lost, if not there could be a possibility to get it back but we would have to research this with our engineers but no guarantee and if you dont have the log file from before this also would be hard for them to resetup the volume. The DSS V6 is using Debian w/ XFS filesystem.