Show progress of dd
Transferring an ISO image using dd can require quite some time and I am left
wondering how long it will take to complete, since dd is silent, by default,
and no information is shown. There are two simple solutions to remedy the
situation.
Instructing dd to show progress before it is launched
The progress=status argument instructs dd to display its progress:
dd if=archlinux-2020.02.01-x86_64.iso of=/dev/sdNNN status=progress
where sdNNN is the device identifier, e.g., /dev/sdb.
Quoting from the manual:
status=LEVEL
The LEVEL of information to print to stderr; 'none' suppresses everything but error messages,
'noxfer' suppresses the final transfer statistics, 'progress' shows periodic transfer statistics
Instructing dd to show progress after it has been launched
If you forget to specify the status information, you can still get informed
about dd progress. Open another terminal and enter the following command.
On Linux:
sudo kill -USR1 $(pgrep ^dd)
On OSX/BSD:
sudo kill -INFO $(pgrep ^dd) # (on OSX)
This displays progress in the dd terminal window without halting the
process.
If you would like to get regular updates of the dd progress, then enter:
watch -n5 'sudo kill -USR1 $(pgrep ^dd)'