# dd if=/dev/zero of=/dev/sdb bs=$((1024*4))
dd: error writing '/dev/sdb': No space left on device
1002267+0 records in
1002266+0 records out
4105281536 bytes (4.1 GB, 3.8 GiB) copied, 2.10549 s, 1.9 GB/s

# head -c 4105281536 /dev/zero | sha1sum
a1750724bfbf0ada57d986f16b26e789a6c61a1d  -
(reverse-i-search)`': ^C
# head -c 4105281536 /dev/sdb | sha1sum
a1750724bfbf0ada57d986f16b26e789a6c61a1d  -

[ 9895.437518] scsi 4:0:0:0: Direct-Access     Mass     Storage Device        PQ: 0 ANSI: 0 CCS
[ 9895.439248] sd 4:0:0:0: [sdb] 30318592 512-byte logical blocks: (15.5 GB/14.5 GiB)
[ 9895.439398] sd 4:0:0:0: [sdb] Write Protect is off
[ 9895.439404] sd 4:0:0:0: [sdb] Mode Sense: 03 00 00 00
[ 9895.439557] sd 4:0:0:0: [sdb] No Caching mode page found
[ 9895.439564] sd 4:0:0:0: [sdb] Assuming drive cache: write through
[ 9895.441922]  sdb: sdb1 sdb2
[ 9895.443517] sd 4:0:0:0: [sdb] Attached SCSI removable disk