Are repeated incremental backups reliable?


assume we do a fullbackup on day 1, then an incremental backup on day 2 and merge it immediately into the fullbackup with “xtrabackup --prepare --apply-log-only --target-dir /backup/full/ --incremental-dir /backup/inc/”. Is there any difference between this merged fullbackup and a new fullbackup that we would perform on day 2 (instead of the incremental one)?

I.e., is it save to perform a fullbackup only once and then only do incremental backups and merge them right after they are finished? Or would it be better to perform a fresh full backup from time to time?

Note that we don’t need to keep different stages of backups, one full up-to-date backup is enough (but a real fullbackup takes so much time that we wouldn’t like to do that every night).