Will your backups work if you have to restore them?
Archive - Originally posted on "The Horse's Mouth" - 2008-09-18 15:26:34 - Graham Ellis
There are a lot of myths surrounding data backups. Ones says that "the more often you take backup everything, the better it is", but actually that only applies to data that's changing. There is little point in wasting a lot of resources repeatedly backing up the same unchanging builds in /usr/local if you're in a stable web server environment where you web site content and MySQL databases are the critical data, with configuration files such as .htaccess being used for any minor tweaks the server needs on a per-directory basis. But using a carefully structured backup strategy could lead to you missing out one critical element, so it's best to check out that your backups are good. How to do this?
Yesterday, I had an eight hour airline flight ... and I had with me a Linux / Fedora laptop and a "complete" set of structured backups from which a restore / rebuild of our web site should be possible. What better opportunity to spend a couple of hours (a.k.a. one battery laptop lifetime) checking that my backups really did work?
I'm pleased to report success; in the time I had, I stripped out delegate's builds of Apache httpd, PHP and MySQL from /usr/local, installed a fresh set using the distributions I had with me as part of the backups, restored the specific config files and then the websites including HTML, CGI, Database and ancillary directories from my backups. And (apart from accessing data from other servers such as the European Central Bank - not available in-flight!) it all worked.
A few more pictures
I wasn't the only one working in flight ... 
An evening flight, the low sunlight over the wing ... 
... and as we flew into the night, cities lay out below us.