Backup is irrelevant for those of you who care about this discussion. LVM/ZFS snapshots are the rule of the land.
While I agree with most of Brian's statements in the article, I respectfully disagree with the statement above, especially the bolded part. Copy-on-write snapshots are EVIL for very large databases operating in a high I/O environment and backup, by no means, is entirely irrelevant. Please correct me if I am wrong but it is my understanding that both LVM and ZFS implement copy-on-write snapshots. Backup may be irrelevant for most sites but not for us.
If, however, by "irrelevant" Brian meant that not important in choosing one database over another, I can agree with that. Why? Because no one benchmarks backup methodologies until backup process starts becoming a major PITA.
Backup methods can be a performance killer when dealing with very large databases. If you're interested in finding out why, and more importantly how, ask me at the conference, come to my scaling MySQL and InnoDB on Solaris session, or check on this blog after the conference.