# dd if=/dev/rbd0 of=/dev/zero bs=1M dd: reading `/dev/rbd0': Input/output error 1104+0 records in 1104+0 records out 1157627904 bytes (1.2 GB) copied, 0.253979 s, 4.6 GB/s zsh: exit 1 dd if=/dev/rbd0 of=/dev/zero bs=1M # dmesg [509307.830921] end_request: I/O error, dev rbd0, sector 2260992 [509307.834828] Buffer I/O error on device rbd0, logical block 282624