There are continual messages along the lines of:
Mar 5 09:37:53 crookserver2 kernel: sd 1:0:5:0: attempting task abort!scmd(0x000000001af04f39), outstanding for 30416 ms & timeout 30000 ms
Mar 5 09:37:53 crookserver2 kernel: sd 1:0:5:0: [sdg] tag#629 CDB: opcode=0x88 88 00 00 00 00 00 00 02 7f 80 00 00 04 00 00 00
Mar 5 09:37:53 crookserver2 kernel: scsi target1:0:5: handle(0x000d), sas_address(0x4433221105000000), phy(5)
Mar 5 09:37:53 crookserver2 kernel: scsi target1:0:5: enclosure logical id(0x500605b003f99080), slot(6)
Mar 5 09:37:53 crookserver2 kernel: sd 1:0:5:0: task abort: SUCCESS scmd(0x000000001af04f39)
This implies there is either a problem with sdg (disk1) or with the hardware to which it is attached.