Everything may go wrong in this process. Make backups, prepare a live distribution that can connect to internet.
Sync your current root filesystem to another location, eg. /NEW_ROOTFS
- Edit
/NEW_ROOTFS/etc/fstab
to mount proper devices - Edit your rootfs synchronization tool (
smith-sync
,btrbk
,dcs-tools
,snapper
, ...) config to backup between correct devices