Tuesday, February 1, 2011

Data Backup Day – February 1, 2011

The first day of each month is as good a day as any to use for the reminder to backup your data.  You DO backup your data, right?  Computer hard drives have moving parts, and anything with moving parts is guaranteed to fail sooner or later.  Even solid state drives like USB flash drives can fail.  CD and DVD media are now said to last as few as 3-5 years, depending on how they're stored, perhaps longer if you're lucky. 

The answer is to maintain multiple copies.  Corporate backup strategies almost always also require at least one of those copies be stored offsite.  That way, if a tornado wipes out your building, you can recover your data from the remote location.  For most people, this would be done by taking a copy to a trusted friend or family member's house.  But consider the recent flooding in Australia, where large areas are underwater, or the aftermath of Hurricane Katrina in New Orleans.  Is a copy at another location in the same city sufficient?  You will have to decide for yourself. 

DVD media
How can we make a backup?  There are many options.  Writing (burning) the data to a CD or DVD is a good choice, as long as you remember to make multiple copies and test them for readability on occasion.  They have the benefit of being very compact.  You could even mail copies to people to store offsite very easily, even to other cities to avoid my disaster scenario above.

USB flash drives
Another choice would be USB flash drives.  There's no really good data on how long they can hold their data over long periods of storage, though, so again multiple copies and occasional testing for readability would be in order.  Since there's no moving parts, at least there's no worry of mechanical failure.  They are even smaller than CD/DVD media, also very easy to mail or transport to offsite locations. A drawback is that they are small, and easily lost if you're not careful. 




External hard drive and USB cable
External hard drives are very available these days.  They typically connect via a USB cable.  A major benefit is that they hold vast amounts of data as compared to CD/DVD and USB flash drives, with some examples reaching two terabytes and more.  There are various physical sizes as well, some small enough to fit in your pocket, others  about the size of a hardcover book.  Mailing these offsite takes more consideration, but is doable.  One downside is that many of these require an external power supply.  Also, being mechanical devices with moving parts, they will eventually fail.

Add an extra hard drive as a mirror copy
Another method many people don't consider is to have a second hard drive in your own machine, set to mirror everything on the primary drive.  This has the advantage of being completely transparent and immediate.  It has the disadvantages of being non-portable, and mechanical.  Balancing the mechanical failure vulnerability is that it's extremely rare for both the main drive and a mirror drive to fail at the same time, which allows you to replace the failed drive and re-mirror the data before the working drive also fails.  The non-portable aspect means no offsite backup.  This one is difficult to implement if you're not technical, as you need to physically install another hard drive, and then get it to mirror the original drive.  Talk to a local computer repair shop if you're interested in this method and not comfortable doing the setup yourself.

One last method is what the tech community is calling Cloud Storage.  That means having some storage space somewhere on the Internet where you can upload and store (and maybe even share) your data.  This could be as simple as a Dropbox-style service, or maybe uploading your tree and data to Ancestry.com or other service designed for genealogy.  The benefits are that the storage is by nature offsite, and almost certainly redundant in that those services maintain several failure mitigation controls.  A drawback is that once your data is out there, you don't have full control over it.  You never know for sure who can access it, and for what purposes.

I would recommend a combination of these methods.  I personally use the mirrored drives approach, and copy my data to DVD as well.  I could do better at the offsite storage part of the equation.  (See, even techs don't always follow their own advice!)

What method(s) are you using for data backup?  Let me know in the comments below!