$ dd if=/dev/zero of=/dev/sda bs=4M seek=238467
dd: error writing '/dev/sda': Input/output error
1+0 records in
0+0 records out
4296736767 bytes (4.3 GB, 4.0 GiB) copied, 0.570141 s, 7.5 GB/s

$ dd if=/dev/zero of=/dev/sda bs=4M count=1 seek=238467
dd: error writing '/dev/sda': Input/output error
1+0 records in
0+0 records out
4296736767 bytes (4.3 GB, 4.0 GiB) copied, 0.569407 s, 7.5 GB/s

$ dd if=/dev/zero of=/dev/sda bs=4M count=1 seek=238468
dd: /dev/sda: cannot seek: Invalid argument
0+0 records in
0+0 records out
0 bytes copied, 0.00559805 s, 0.0 kB/s

$ dd if=/dev/zero of=/dev/sda bs=4M count=1 seek=238466
1+0 records in
1+0 records out
4194304 bytes (4.2 MB, 4.0 MiB) copied, 0.0500875 s, 83.7 MB/s