What is a Backup Window & Why it Doesn’t Matter
What is a backup window, anyway? If you’ve spent any time managing backups, you’ve probably heard people obsessing over backup speeds. But here’s the thing – no one actually cares about your backup speed. What they care about is how quickly you can get their data back when things go wrong.
This blog post summarizes the main points of my latest podcast episode. If you’d like, you can listen to it or watch it at https://www.backupwrapup.com/
What is a Backup Window Really About?
Let’s get real about what a backup window means in today’s environment. Back in the day, we were locked into strict backup windows because backups hammered server performance. You’d get your window – maybe 10 PM to 6 AM – and you had to squeeze everything into those eight hours or face the wrath of the production teams.
Modern Backup Windows: Beyond Traditional Constraints
These days, what is a backup window looks totally different. With technologies like block-level incrementals and source-side deduplication, we’re not stuck with those rigid timeframes anymore. The performance impact is way lower, which means you can often run backups whenever you want. Some folks are even doing backups every few minutes.
Why Your Recovery Speed Trumps Backup Speed
Here’s where the rubber meets the road – nobody’s going to pat you on the back for fast backups, but they’ll definitely notice slow restores. Let me tell you a story: I once worked at Motorola and inherited a backup system with tape drives that could write data just fine. But when I needed to restore? Complete failure. The drives couldn’t read. At all. Talk about learning the hard way that backup speed means nothing if you can’t get the data back.
Testing What Matters
If you want to know what is a backup window worth, test your restores. And I don’t mean just checking if a single file comes back. You need to test:
- Full application recoveries
- Recovery groups (all those dependent systems)
- Different types of restores (files, databases, VMs)
- Large-scale recoveries
Remember the dedupe tax too – just because your system can back up at a terabyte an hour doesn’t mean it can restore at that speed. I’ve seen systems with a 90% dedupe tax, meaning restores ran at one-tenth the backup speed. Ouch.
Make Recovery Speed Your Priority
Modern solutions are addressing these challenges. Technologies like instant recovery and pre-staged recovery environments can dramatically improve your restore times. But you won’t know if they work unless you test them. Start small, work your way up, but make sure you test before you need it.
Written by W. Curtis Preston (@wcpreston), four-time O'Reilly author, and host of The Backup Wrap-up podcast. I am now the Technology Evangelist at S2|DATA, which helps companies manage their legacy data