The -rollback flag just controls what happens when the rollforward runs
out of journal records at the end of the process. If there are
uncommitted transactions it rolls them back instead of assuming "future"
journal files would complete the transactions and dispose of them in the
If whatever your incremental rollforward is doing is working as you
expect and require, adding -rollback won't stop it working. It may
however cause transactions to be lost that would otherwise have been
recovered in future.