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Thirteen things you really need to know about backing up
In case you lose your data - whether it be one file or your whole computer.
You might find the disc fails, or you might literally lose the USB stick.
Simply, taking copies of files and storing them safely.
But there is more to it than just having a copy of the latest file.
There are two aspects to backup - data security and data integrity. Data security is that the file ‘a’ exists and you can restore it. Data integrity is that the information in the file is correct.
Let’s take an example: you make a report every month. To save time, you open last month’s, edit it and then save it under a new name. However, one month you forget and just press ‘save’. The file still exists, so there is data security. Yet the file now contains this month’s data rather than last month’s, so data integrity has been lost. Or worse, the file is corrupted and won’t open.
A proper backup system covers both aspects.
These systems are better than nothing, but are aimed at sharing files between computers. Delete a file from your computer and it goes from everywhere. The same with editing a file - your mistakes are replicated.
So it doesn’t meet my definition of backing up. You need something else.
Backing up and archiving are similar but subtly different. Backing up takes longer but captures changes in a file over time. Great for living data like spreadsheets. Yet some items, such as photos, don’t change. So we take two copies and store them safely. Then we don’t need to spend time backing them up.
There are three types of backup.
The first is a system image, where you take a ‘snapshot’ of the whole computer.
If anything goes wrong, then you can put this image back onto the computer and you are back as things were when you took the image. This is great if the disc dies completely and you have to replace it. It makes life a lot quicker and easier. Most imaging systems will allow you to restore single files or folders. But it takes time and a lot of space.
This is what the recovery discs contain that you are often encouraged to create when you get a new computer. Just remember that your computer will go back to how it was when you took the original image.
Second, Full backups are more focussed on data files and assume that you have the DVDs to put the programs back on the computer. So a full backup takes a copy of every file and folder that you have told it to. This still takes time and quite a bit of disc space.
So thirdly we have the incremental backup. Now, not every file changes between backups, so the incremental backup only takes a copy of files that have changed since the previous backup. The backup system makes it look like a full backup to the user. Quicker and effective.
Say you only keep one backup and do that very night. You do some housekeeping and delete a load of files. Tomorrow you realise that you should have kept one of the files. Sorry, it’s not on the backup you took last night.
A backup system will also copy a file, regardless of what it contains, even inaccurate or corrupted. So for the data integrity aspect of backing up, we need to retain a number of historical copies of files so that we can always wind back to a good one. These are called versions. A decent backup system will let you go back through multiple versions of the file.
After a fairly poor start, cloud backups (onto systems via the internet) have matured. The greatest advantages of a cloud backup are that it is offsite and your backups are backed up.
The drawbacks are that you have to upload and retrieve via the internet, so if your broadband performance is slow, you may be waiting for several days days!
There is also a potential difficulty that it will back up whenever you have an internet connection, so when you are out and about you may run up some hefty data charges unless you remember to turn it off.
But on the whole a good solution for fast internet connections.
Local backups are pretty much the opposite in pros and cons. It becomes a really great solution if you can place your backup storage device, say a disc drive on the network in a different building. If you work in a garden shed, can you network to the house?
In a nutshell, anything you can’t afford to lose. That means not just documents but emails, contacts, internet bookmarks……
Programs you should be able to reload from the original CD/DVDs or by downloading them again, depending on how you got them in the first place. So there is no need to back them up.
That depends on how often the files change and how important they are.
My rule of thumb is to keep increasing the frequency of backups until the effort or impact of backing up is greater than that of recreating the file since the last backup. At a minimum I’d suggest once a week.
Well, a bad policy is to backup your data onto the same disc as the original data! Whilst not quite as bad, even using a second disc in the computer leaves you exposed.
The ideal backup policy involves having multiple devices or systems holding your data in different locations. For example, the grandfather-father-son approach to local backup uses three backup devices in rotation, with the two not in use stored elsewhere in case of fire or theft.
Each device first takes a full backup and then incremental backups at the end of the period (say a week) it is swapped for the next device in rotation.
Thus you have three backup periods to fall back on, giving you at least three versions.
Most competent backup systems will delete the oldest copies when the backup medium (Disc or cloud) becomes full.
If you start deleting backup files, then you may well delete a vital part of the sequence. Incremental backups require a full backup to base themselves on. If you delete the full backup, the incrementals are going to get very confused and may well not work.
Obvious, maybe, but do try it. I knew of one company that religiously backed up every night. This was in the days that we used tape machines for backup. When they did need to recover from a backup there was nothing on the tapes. No-one had cleaned the tape heads for years so the signal couldn’t get to the tapes!
So it is worth verifying the backup as part of the backup system if possible, but even better to restore files ever so often to a new location - don’t overwrite the ‘live’ ones!
Not always. Both Windows and Apple computers have perfectly competent local backup systems for general use built in.
Windows 7 has ‘backup and restore’, Windows 8 uses ‘file history’ and Apple has ‘Time Machine’.
Some internet security systems have backup built in.
Finally there are commercial products if you have more sophisticated requirements than most
So get backing up and keep your cool when you need to get that file back!
This is one in a series of guides from the flying doctor to help you keep your computer safe. Visit our web site to view more.