After a month of troubleshooting, I seem to have two main problems with my system. I first encountered issues with the RAID, which used a #HighpointTech card and #WesternDigital drives. I started an RMA with Hpt, since the card would no longer detect any drives. (The drives always pass tests with #smartmonctl.) I also discovered errors associated with one #Corsair DRAM DIMM. I started an RMA for that as well.