Le 11/06/2019 à 13:36, songbird a écrit :
what i'm not sure of is if you need to bother with putting the grub bootloader on it so at the end where it asks you perhaps you can skip that step.
IMO installing GRUB can be desirable for two reasons.1) Obviously, it allows the drive to boot by itself so that you can move it into another machine, or remove the current boot drive, or change the boot order.
The OP uses legacy boot, but be aware that this won't work the same with EFI boot : installing a second instance of a Debian system will overwrite the existing EFI boot entry "debian".
2) It creates a grub.cfg file which provides hints about kernel parameters and so on when running update-grub from another system.
Warning : you should disable os-prober when running update-grub on a non-boot system, otherwise it may happen that update-grub adds duplicate menu entries (sometimes hundreds !).