Parity2 appears to be failing, run an extended SMART text to confirm.
May 31 10:35:32 godzilla kernel: ata4.00: exception Emask 0x0 SAct 0x1ff80 SErr 0x0 action 0x0
May 31 10:35:32 godzilla kernel: ata4.00: irq_stat 0x40000008
May 31 10:35:32 godzilla kernel: ata4.00: failed command: READ FPDMA QUEUED
May 31 10:35:32 godzilla kernel: ata4.00: cmd 60/00:38:e0:d3:67/04:00:08:00:00/40 tag 7 ncq dma 524288 in
May 31 10:35:32 godzilla kernel: res 41/40:00:90:d6:67/00:00:08:00:00/00 Emask 0x409 (media error) <F>
May 31 10:35:32 godzilla kernel: ata4.00: status: { DRDY ERR }
May 31 10:35:32 godzilla kernel: ata4.00: error: { UNC }
May 31 10:35:32 godzilla kernel: ata4.00: configured for UDMA/133
May 31 10:35:32 godzilla kernel: sd 5:0:0:0: [sdm] tag#7 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte=0x08
May 31 10:35:32 godzilla kernel: sd 5:0:0:0: [sdm] tag#7 Sense Key : 0x3 [current]
May 31 10:35:32 godzilla kernel: sd 5:0:0:0: [sdm] tag#7 ASC=0x11 ASCQ=0x4
May 31 10:35:32 godzilla kernel: sd 5:0:0:0: [sdm] tag#7 CDB: opcode=0x88 88 00 00 00 00 00 08 67 d3 e0 00 00 04 00 00 00
May 31 10:35:32 godzilla kernel: print_req_error: I/O error, dev sdm, sector 141022864
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022800
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022808
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022816
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022824
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022832
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022840
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022848
May 31 10:35:32 godzilla kernel: md: disk29 read error, sector=141022856