Friday, March 01, 2013

Backups and Archives - knowing the difference

This entry resulted due to the failure of one of my home backup drives
"Oh one of my backup drives failed"
"One? Why do you have more than one?"
"Because otherwise it wouldn't be a backup"

In the most simple of terms if you have a computer you probably want to make sure the data on it is safe. Cloud backup is fine, but they tend to have limitations and upload speeds aren't the same as download speeds as anyone trying to upload a video to YouTube has probably discovered.

For such things, and for peace of mind, a local external and portable hard drive is a good option; particularly given how cheap they are nowadays.

With disk plugged in data is copied across either by manually picking and choosing or by letting the Operating System run its own backup software. All done the user can now retire safe in the knowledge that if anything happens to the computer the data can still be retrieved. Or not.

From experience and conversations there are two very large blind spots that seem to occur to users and backups.

First up is actual physical damage and can be demonstrated by asking a very simple question "Where do you keep your backup?" If you answered "Next to the computer" than that's hardly secure. Imagine if someone broke in and stole your computer, are they going to ignore that hard drive next to it? What if the computer catches fire; where will the fire spread to - the back-up right next to it. I'm not saying be paranoid, but try at least to keep the back-up and the actual thing you've backed up in separate locations. If you're American think of it as keeping the President and the Vice President apart as much as possible.

The second blind spot is whether the back-up is in fact still a back-up? This is where that "Huh?" came in at the beginning. The question in this case is "Do you delete things off your computer then or some time after you've backed them up?" If the answer is yes then you do not have a back-up; you have an archive. It's not a back-up if there's only one copy of the information. The blind spot here is being concerned about information being lost from a computer, but not what would happen if information was lost from the 'back-up'.

This is why I have two 'back-up' discs. I have information on the computer, and information on disk 1 that is no longer on the computer; so it's backed up to disk 2. To keep life simple I just keep both discs the same and keep both away from the computer. For a home user this may not seem as crucial particularly with so much being kept on the Cloud, but these are things that could be vital to a business.

Consider my district council's new office block with its own server room. The question I asked at the time from seeing the plans was "So where are the backups kept?" In the same room? I hope the flaw in that is now apparent. The same can be said for on-site redundancy such as some of the RAID system, by which data is kept across multiple drives in multiple cases in case a hard-drive fails. Excellent, and all these drives are kept in the same rack? Whoosh one fire and bye-bye data. Copy off old data and store it next to the main computers for easy access... burn baby burn.

Just keep those two points in mind, it doesn't take much thought to make a potentially massive difference if something goes wrong.

Slightly off-topic the question has been posed repeatedly of exactly when backups should be done. Often following a computer meltdown and a "Oh it's been at least two months since I did a backup"

The answer is do a backup if you would miss the data that hasn't been backed-up yet.

Writing your Magnus Opus? Probably want a back-up after every major edit. Updated your browser bookmarks... probably not so vital. If in doubt keep a simple USB stick and just back-up whatever document etc. you've been working on just to keep it safe until you decide to do a 'proper' back-up.

Oh and yeah speaking of that - if you're working off a document stored on one of those sticks it's not a 'back-up' despite its location; it's the original.