# blkpr > Register, reserve, release, preempt, and clear persistent reservations on a block device that supports Persistent Reservations. > More information: . - Register (command) a new reservation with a given key on a given device: `blkpr {{-c|--command}} register {{-k|--key}} {{reservation_key}} {{path/to/device}}` - Set the type of an existing reservation to exclusive access: `blkpr -c reserve {{-k|--key}} {{reservation_key}} {{-t|--type}} exclusive-access {{path/to/device}}` - Preempt the existing reservation with a given key and replace it with a new reservation: `blkpr -c preempt {{-K|--oldkey}} {{old_key}} {{-k|--key}} {{new_key}} {{-t|--type}} write-exclusive {{path/to/device}}` - Release a reservation with a given key and type on a given device: `blkpr -c release {{-k|--key}} {{reservation_key}} {{-t|--type}} {{reservation_type}} {{path/to/device}}` - Clear all reservations from a given device: `blkpr -c clear {{-k|--key}} {{key}} {{path/to/device}}`