Sunday, 8 September 2019

dd - useful flags

For burning a hybrid media image to a USB stick

dd if=debian-10.1-amd64.iso of=/dev/sdb obs=4M status=progress oflag=sync

The critical things here:

/dev/sdb is wherever your USB stick is recognised.

obs=4M - 4M rather than 512k chunks written to the stick [output block size

status=progress gives you some idea of how far through you are

oflag=sync - syncs to force data caches to flush - the OS reports back impossibly fast transfers and it then takes minutes to actually write the data.

Now that USB sticks can be metal cased and there's no obvious indication of activity, this helps a lot.