Yees cbbackup already accounts for this
Just remember its a point in time backup. Anything written after that backup can be lost in event you lose the disk storage or have a logical corruption. There is no write append LOG.
“You must back up and restore your entire cluster to minimize any data inconsistencies. Couchbase is always per-item consistent but does not guarantee total cluster consistency or in-order persistence.”
The cbbackup will backup the data buckets - I know it misses some other objects. Views and indexes maybe for example.
BUt it doesnt have a mechanism like a RDBMS to do full recovery. No WAL.