Tuesday, November 21, 2006

Backups: Rotation of backups

What’s your approach? I’m asking... because for SMB clients, I’ve heard literally every possible combination of tactics, all with the same strategic aim - protecting the business.
Here’s what I do - not saying it’s perfect... certainly not saying it’s the only way... but it’s working for us internally, and is basically what we do/recommend for clients (depending on their risk profile, budget, and expectations).

  1. Nightly full backups of everything that’s "business critical", with a two-week rotation.
  2. At the beginning of each week, the last completed backup is taken off-site, and the previous one is returned.
  3. At the end of every month, the most recent completed tape is taken out of rotation and stored off-site.
  4. At the end of the year, a tape is taken off-site and stored permanently.
This gives us the ability to restore data from any day in the past two weeks, end-of-month for the past 12 months, and end-of-year for the past N years. The reason that I chose nightly full backups is because relying on the weekly tapes and daily incrementals introduces more risk. Now, there are some other components not covered here - archive shares, web servers, and so on... those are all covered by a separate monthly policy for non-business-critical assets.

What do you think? Obviously the more tapes we include the more options we have... but in general terms do you have any suggestions for improvement?


Anonymous said...

This is a great setup an exactly what I do with with my clients.

Client with lots of data I've got the dilemna of full backups daily. I have no answer yet, so we've been rotating two 750 gig drives every other week, each drive containing 5 days of backups.

Not a good system as we can't go back a month, a year but currently I have no other answers.

Thoughts, suggestions?

Nick said...

We considered using Microsoft's DPM internally. The pricing doesn't look too prohibitive ($950 for 3 servers as I recall).

Obviously, this isn't going to cover your off-site concerns, but it is really useful for doing quick point-in-time recovery for the last "X" number of days. You could combine it with a rotating hard drive approach, such that myabe you used DPM for 4-weeks of data, and then 2 or three hard drives for monthly backups which you take off-site.

Also, there's a number of internet-based backup services that I've looked into - including some where you just buy the software and configure everything yourself. So far, I havn't been really impressed with anything.

I still like properly-sized full nightly backups with end-of-week/month/year stored off-site.