Given the totality of your situation, I think it might be wise to take this opportunity to overhaul things completely. 4.7 uses ReiserFS exclusively, which is no longer recommended and performs very poorly with drives larger than 2TB.
Please list all the components in your current system, motherboard, cpu, memory, power supply, HBA's, hard drives, etc.
Also, how much storage is currently occupied?
My initial thought is to back everything up to an external drive, and start over with a new version of unraid and whatever else is needed.