A couple of nifty things with dd Be cautious, for example the conv=sync,noerror options should be considered essential
create a backup image of disk
# make a backup of disk to image file
dd conv=sync,noerror status=progress bs=512 count=21459327 if=/dev/sdX of=/sdX-Backup-512k-blocks.img.gz
# if status=progress option is unavailble, you can still get progress
# by sending USR1 to the running dd process.
# i.e.:
kill -USR1 <PID>
# to save space, compress the data with gzip:
dd bs=512 count=31459327 if=/dev/sdX | gzip -c > /sdX-Backup-512k-blocks.img.gz
# and to restore the image:
gunzip -c /image.img.gz | dd of=/dev/sdX
# another trick is to pipe `if` to `of` like so
# (has been reported to increase throughput)
dd if=/dev/sdX | of=/dev/sdb
check write speeds
sync && dd if=/dev/zero of=./tempfile bs=1M count=1024 && sync