https://access.redhat.com/documentation/en-us/red_hat_amq/7.6/html-single/migrating_to_red_hat_amq_7/index#producer_policy_configuration_properties

For the address, set <max-size-bytes> to the size at which the producer should be throttled, and then set <address-full-policy> to BLOCK.
Configuring these two properties will also throttle your existing AMQ 6 OpenWire producers.
 

It should be PAGE instead of BLOCK to mimic how AMQ 6 works. In AMQ 6 producer flow control will not kick in until the disk is full, it is similar to "PAGE". AMQ7's BLOCK will kick in premature even when the journal have plenty of disk. AMQ7's BLOCK is similar to AMQ6's PFC when using vmCursor (default is storeCursor).