Before going into kernel panic and refusing to reboot again, restbase2003 was writing continuously "attempting to write to an offline device"
During the restart, I saw
Embedded RAID : Smart Array P440ar Controller - (2048 MB, V2.52) 5 Logical Drive(s) - Operation Failed - 1719-Slot 0 Drive Array - A controller failure event occurred prior to this power-up. (Previous lock up code = 0x13)
the system is back up but I don't intend to put it back into rotation until hardware is inspected.