[andreasha]

You can clone it while running as well [0]. For speed make sure the adapter is USB3.0 and plugs into one of the USB3.0 ports on the pi and also that it supports UASP and enable trim on the drive [1].

[0] https://github.com/billw2/rpi-clone

[1] https://www.jeffgeerling.com/blog/2020/raspberry-pi-usb-boot...