Took another look a the last diags to see if the emulated disk was mounting and there are more disk errors, now disk4:
Jun 10 17:07:44 Warptower kernel: sd 11:0:2:0: [sdd] tag#801 ASC=0x4 ASCQ=0x0
Jun 10 17:07:44 Warptower kernel: sd 11:0:2:0: [sdd] tag#801 CDB: opcode=0x28 28 00 ae ad 2b 40 00 03 38 00
Jun 10 17:07:44 Warptower kernel: blk_update_request: I/O error, dev sdd, sector 2930584384 op 0x0:(READ) flags 0x0 phys_seg 103 prio class 0
Jun 10 17:07:44 Warptower kernel: md: disk4 read error, sector=2930584320
Jun 10 17:07:44 Warptower kernel: md: disk4 read error, sector=2930584328
Jun 10 17:07:44 Warptower kernel: md: disk4 read error, sector=2930584336
Jun 10 17:07:44 Warptower kernel: md: disk4 read error, sector=2930584344
Looks more like a power/connection problem.