It is always said to do backups, backups still, more and more backups. What we tend to say less often is that until the data have not been successfully restored a backup is useless.
A striking example is the case of Ma.gnolia , social site where it was possible to store brand pages on the Internet. On January 30 last, the site has undergone a catastrophic crash of the MySQL database 5, leading to the site makes the cut. This crash was due to data corruption spread over time (not detectable a priori without any real consistency check), which also corrupted backups. A passage by specialists in data recovery has unfortunately given nothing either, which means a total loss of nearly 500 GB of data users and the actual death of the site in its current version. Fortunately, caching systems on other websites ( FriendFeed , RSS, etc.) have enabled some users to recover some of their data.
Here's a podcast where the responsible Ma.gnolia explains a little more detail what happened:
Citizen Garden Episode 11: Whither Ma.gnolia? from Larry Halff on Vimeo .
The main lesson to remember for an operator of backups is tested regularly here until the end of his recovery process data. It is also useful, although technically difficult or impossible to conduct audits of data consistency and to save backups.
Tags: Backup , Disaster Recovery
