I created a persistent USB thumb drive boot with LUKS for drive encryption (250 MB /boot and then 7.5 GB ext3 root). There's no swap partition because this is just to store some private files.
I want to make two or three copies of this thumb drive to store apart in case one gets destroyed/lost.
When I am booted from that thumb drive
, can I plug in a same sized drive and just do a
dd if=/dev/sdb of=/dev/sdc
command to make a copy of itself to another thumb drive without booting to another host OS? This way when I make changes to one (such as to update the OS, apps, or data), I could then just copy the entire thumb drive over to the other two while still booted in the original USB.
Or would I effectively have to shut down, boot to my normal host OS (or other), and then copy the thumb drives when not booted into them.