Before I start a story about the data recovery case I worked on yesterday, here's a quick tip - having a database backup does not mean you can restore from it. Always verify your backup can be used to restore the database! If not automatically, do this manually, at least once a month. No, seriously - in most of the recovery cases I worked on, customers did have some sort of backup, but it just wasn't working, complete and what not. Someone set it up and never bothered to check if it still works after a while.
Anyway, this post is not really about the backups but rather about few interesting things I learned during last recovery case.
First, some facts about the system and how data was lost:
- MySQL had a dedicated partition on XFS file system