Data Backup
Keep your data backed up
The problem
A while back I got an urgent phone call from a friend who is a researcher. He had opened an email with an attachment from an unknown source and now all his precious Word documents were encrypted. I quickly sniffed out that he was victim to something known as ransomware. The first thing I asked him was if he had any backup of his work. Unfortunately for him the answer was negative and he ended up paying the criminals a hefty fee to get his documents back. However, in another case, when one of my clients had their server messed up by ransomware they were luckier, because they were able to rectify the situation by reverting to their daily backup.
Another of my clients had their main computer infected and they cleverly switched off the computer as soon as they got the message from the extortionists and then got their IT man to move the hard disk to another computer. This way the ransomware did not have time to encrypt all the files. They then tried to decrypt the files that did get infected, but without success.
Yet another was doing regular backups for over twenty years. There was a change of staff and no backups for six months. Then the hard drive failed! Six months of data lost!
These are only two of the reasons that regular backups of computer files are necessary. There are many others: loss or theft of laptop, file corruption, inadvertent deletion of file to name but a few.
The solutions
One form of automatic backup available is where the OS creates an automatic backup of all modified files at regular intervals, let's say twice a day. This has saved me on numerous occasions where a database file got corrupted or I made some changes to my code and then realised that I needed to go back to what I had before.
However, this method has a gotcha! It does not help you if your hard disk fails or you lose your laptop. In the case of ransomware the backups can also sometimes get encrypted.
Another solution is a backup program that backups to an external hard drive. Windows comes with a built in backup feature available from the Control Panel, Mac has a built in backup feature "Time Machine" and Unix has "Déjà Dup".
These days where fast internet connections are the norm, online backup has become very popular. You will have an application running in the background that will encrypt your files and then upload them to the backup server. They will be stored in the cloud. You should be able to select which files to backup and create a schedule specifying when to do the backup. Choose a time when you are not going to be using the internet as it will likely make heavy use of your connection. Should you ever need them you will be able to restore the files from any location, using your username and password.
There are many companies offering paid online backup services and some even offer free storage up to a certain quota, which may be enough to cover your essential files.
How many backups?
In principle one backup should be enough. So why is it not a good idea to dispose of yesterday's backup when you do today's? In the case of database systems, you may not notice the corruption immediately. Sometimes it takes months until you realise that so and so was deleted from the database by mistake or that a certain memo field is showing gibberish due to corruption even when the rest of the data is OK.
Generally I would recommend keeping daily backups for a week, weekly backups for a month and monthly backups for a year. Since only the delta is saved you are not actually using up disk space for each backup as only the changes are using up fresh space on the backup server.
Am I really backed up?
Often a company will set everything up correctly, just to find out that at the critical moment when they need to restore the files, that the backup stopped working six months ago! Or that the employee supposed to be doing a backup each evening on to a removable disk got fed up and has not got a recent backup available.
It is paramount that there be a mechanism in place to ensure that the backups are actually being done and that they are readable. One sure way of doing this, is by calling up the one in charge of the backups once in a while and asking him to restore a couple of files. But then who is going to be in charge of reminding you to call him up?!
