Revision for “Backup 1 – What to backup.” created on 3 November, 2014 @ 1:25
Backup 1 - What to backup.
Backing up a computer is an essential task, but for most individuals and small businesses, it is something they know needs to be done but they never quite get around to doing it. Then one day they have a problem that needs a backup, and they realise that it either doesn't exist, or is inadequate. <!--more-->The first thing to understand about backups is that they are insurance against failure, and so should be approached from a risk management perspective. Asking the following questions is key to getting a backup strategy that works for your environment. If your computer system was totally destroyed: <ol> <li>What components (files, applications, etc) do you need to be operating fully again?</li> <li>How urgently do you need each of those components?</li> <li>How often is it changed?</li> <li>Are there any ways to get those components without using a backup?</li> </ol> The answer to question 1 tells you what to include or exclude in the backups - i.e. the scope. It is usually incorrect to assume that everything needs to be backed up. Use a file browser (Windows Explorer, Finder, etc) and have a good look at each folder asking the question: "How much of a problem would it be if this folder didn't exist?" One thing to make sure does get on the list is emails. These are usually hidden away from the "normal" folders on a disk and can be overlooked. Another area is databases. These are even more tricky than emails as the exact location of the database is dependent on the application, and you will need to check the application's documentation to know where this is. The answer to questions 2 and 3 tell you several things, but in particular how you should back those components up. The key to question 2 is asking "If this component was missing, in normal operations how long would it take before someone noticed it was missing?" That tells you how much of an impact it has on your business. Components that will be noticed quickly - say within an hour - may be candidates for simple backups that have a copy held on site for quick restoration. Bear in mind that restoring from a full backup is often measured in hours. You may also consider having a set of emergency procedures to use that don't require a computer. For example, phone orders could be recorded on a paper form and entered when the system was restored. You could also look at ways to utilise other computers to do the same job assuming that only one computer is affected. Question 4 can help minimise the amount of data being backed up. This does reduce the time for backing up, but more importantly reduces the storage media required for the backup, and over time this can make a big difference. For example, many programs come on CD/DVD and can be re-installed from there. Many computers, particularly laptops, have hidden sections on the disk that can be used to restore the computer back to the way it was when you first bought it. If you have another reliable copy of that component, then in most cases there is no need to include it in the regular backup process. The actual process of deciding what to back up ends up being a bit more complex than this description because there are grey areas and circumstances that are specific for each office. However these are the principles and it is just a matter of working out how to apply them to the grey areas. The next things to consider are when and how which are the next two topics in this series.