Data Damage Control

A wise geek once asked me "What's the most expensive part in a computer?"

The answer of course: the data.

All the other parts are easily replaced. It's only money for the hardware and you're back in business again. But what about getting all your settings, your emails, documents, pictures, music etc back?

No matter whether you use your computer for business or personal use, do you have a tested disaster plan? Does the thought of losing all your data scare you?

Working as a young draftsman, I once accidentally deleted about three months worth of work, having no other copies except the printouts, I had to redraw them all over again. I'm not the only person this has happened to, and there's no reason it needs to!

Luckily having backups of your computer is not as expensive as an insurance agency, however it does require regular action to save your most recent work.

We can split backup types into two main areas: Operating System and Data Files. The method of backing up the two should be very different. When backing up and restoring an Operating System, the method needs to be able to take a snapshot of the disk in non-running state so that it's going to be a usable backup. You might hear people referencing "bare metal recovery" which means if your system self-destructs you can quickly get running again with brand new hardware.

Operating System backups might not be as useful to some people, who just use the OS the computer came with and just buy a new machine with OS installed when their computer gets old or breaks. But even those people would benefit from having an initial or regular OS backup. What happens in the case where a software install goes completely wrong and a system rollback doesn't get it going again? It's back to the drawing board...

I personally use Operating System backups after completely setting up a new machine, so I've got a good solid baseline for the machine. Down the track it will save the hours of work installing everything from scratch again. It's also handy when installing software temporarily to test: I recently evaluated half a dozen antivirus software and wanted an identical start-point for each, and didn't want a load of garbage left over afterwards.

There are plenty of backup solutions available for all the major operating systems. http://en.wikipedia.org/wiki/List_of_backup_software has a good starting list. My recommendation for Operating System backups is clonezilla as it boots from a CD or USB disk and can back up all Operating systems across the network or to another disk.

As for data backups, it's less about snapshots and having incremental data, so that you have speed and storage efficiency. There are a lot more options for data backups. One very good one is BackupPC backuppc.sourceforge.net but is aimed more for a bunch of networked computers. Backup software that comes with some external hard disks also do the job well.

The most important parts of a backup solution are:

• Operating System backup so that quick recovery of the machine is possible
• Regular incremental data backups so that accidentally deleted files, versions of documents etc are accessible.
• The backup system must have the capacity to store enough data to keep a worthwhile amount of data
• The speed of recovering a single file must be fast and easy enough so that it's actually useful
• There must be an offsite backup plan, no use having the data in the same box or office, in the case of a power spike blowing up equipment or an office fire burning it all down. Some data deserves more care and should be kept in different cities or countries!

Some notes on the various backup media:

• CD's and DVD's are limited in size now. Blue-ray discs might hold a fair bit now. Make sure you get discs that are long-life.
• Tapes still have high capacity but seeking for data can seem to take forever
• Hard disks are cheap and fast for backups and recovery but can develop bad sectors. Best to have multiple copies or a RAID10
• Online backup services are now available, the link speed is the limiting factor, especially when there are large files or changes.

Got a favourite backup software or disaster story to tell? Leave a comment below!