Also, the following appeared in dmesg referencing the same bad LBA 3299402936:
[49702.067452] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [49702.067457] sd 0:0:0:0: [sda] tag#0 Sense Key : Medium Error [current] [49702.067459] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unrecovered read error - auto reallocate failed [49702.067463] sd 0:0:0:0: [sda] tag#0 CDB: Read(10) 28 00 c4 a8 e4 00 00 02 00 00 [49702.067465] print_req_error: I/O error, dev sda, sector 3299402936 flags 0 [49704.912179] sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [49704.912185] sd 0:0:0:0: [sda] tag#0 Sense Key : Medium Error [current] [49704.912189] sd 0:0:0:0: [sda] tag#0 Add. Sense: Unrecovered read error - auto reallocate failed [49704.912193] sd 0:0:0:0: [sda] tag#0 CDB: Read(10) 28 00 c4 a8 e4 b8 00 00 08 00 [49704.912197] print_req_error: I/O error, dev sda, sector 3299402936 flags 0