dd aparece quando o dispositivo para o qual você está gravando não tem mais espaço. Isso significa que você terminou com sucesso a sua escrita, não há mais espaço para escrever.
[cs-server@cs-server release_script]$ ls /media/182147d8-104d-4194-8d42-d5ccccbd4dd6/
bin boot dev etc home lcc lib logs lost+found media mnt nohup.out proc rgw.log run sbin srv sys tmp usr var
[cs-server@cs-server release_script]$ df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/vg_csserver-lv_root
51475068 24206676 24646952 50% /
tmpfs 8142840 52760 8090080 1% /dev/shm
/dev/sda2 487652 109408 352644 24% /boot
/dev/sda1 204580 264 204316 1% /boot/efi
/dev/mapper/vg_csserver-lv_home
1862327048 336197068 1431522620 20% /home
/dev/sdb3 950168 538000 359740 60% /media/182147d8-104d-4194-8d42-d5ccccbd4dd6
/dev/sdb4 73786976294838108032 73786976294837688900 419132 100% /media/182147d8-104d-4194-8d42-d5ccccbd4dd6_
/dev/sdb1 253871 189863 50901 79% /media/mel-boot
/dev/sdb2 999320 8880 938012 1% /media/mel-data
[cs-server@cs-server release_script]$ sudo dd if=/dev/zero of=/dev/sdb3 bs=8192
[sudo] password for cs-server:
dd: writing '/dev/sdb3': No space left on device
131073+0 records in
131072+0 records out
1073741824 bytes (1.1 GB) copied, 0.397365 s, 2.7 GB/s
[cs-server@cs-server release_script]$
[cs-server@cs-server release_script]$
[cs-server@cs-server release_script]$ ls /media/182147d8-104d-4194-8d42-d5ccccbd4dd6/
[cs-server@cs-server release_script]$