Both. And cpio. And Amanda. And ZRM for MySQL.
I don't mean to be flip, but neither is better,
overall, than the other. They are different and suitable to different situations. I use all of the backup tools and software mentioned above, and I look for redundancy in my backups.
I use rsync, as needed, to keep large radmind directories synchronized between servers in different buildings. That doesn't run automatically. It is in a script run by hand when radmind directories have been updated on one of the servers, tested, and found to be all right. Those changes are then rsync'ed to the other servers.
I use cpio in a script that finds files that have been changed in the administrative offices' home directories, pipes the list of files to cpio, and sticks it in a daily incremental backup directory on an archive partition where they are kept for 10 days.
I use tar to backup my Amanda home directory, along with indexes and configuration files, to another server right after Amanda completes it's daily backups. Again, those are kept for 10 days. It happens that all that stuff is also backed up by Amanda to tapes on the other server, so I can pick it up going back a few months.
I use Amanda for my routine daily backups of all the servers across the network (for multiple departments), with a tape cycle that goes back a few months. Amanda, in turn, uses ufsdump underneath on Solaris servers with ufs file systems, and gtar on linux systems and Solaris systems with zfs file systems. While that catches the MySQL data directories, it is not safe to rely on these backups for MySQL. They may work much of the time for MyIASM, but they will fail sometimes, and they will not work for InnoDB.
ZRM for MySQL integrates all the proper methods for backing up MySQL. If you set it up, it will manage the backup of the full database using appropriate methods such as mysqldump after flushing and locking tables and it will use the binary log file to handle incremental backups. It puts all the resulting backup files in a directory on disk. If you set it up on another server, it will access your MySQL server and the backups will be on the other server. If you configure Amanda to catch that directory, and you schedule things so that ZRM runs before Amanda, then you will have those backups out to tape, disk (virtual tapes), or the cloud (S3).
I also use root disk mirroring and data array zfs raidz2 (equivalent to raid6) with a hot spare. The zfs file system allows me to use daily snapshots for important things.
All of these together give you the kind of redundancy that assures you that you won't lose anything (with very good probability
).
