The hazards and the advantages of synchronising in the cloud

Some tools are like weapons: You can’t let inexperienced people handle them. Yet, they can be very useful.

Synchronising data is often seen as a panacea. This is at least how those who design software applications present it. They want you to make use of the automatic synchronisation feature for your contacts list, your files, between various devices, smartphones and computers, between data you store in the cloud and data you keep on your local hard disk or smartphone.

Per se, it is a great thing, definitely, that is when it is well understood and under control, especially when the cloud is the go-between. The simplest case would be the following: Your files are stored in the cloud (Dropbox, OneDrive, Google Drive). You are also running two laptop computers, one at home and one at your workplace. Whenever you add or change a file in one of the three locations, synchronisation takes care of updating the same file in the other two locations. This is great for it lets you see the same file from any of the many locations while at the same time providing a security backup set, since all files are available in three copies.

Why is the concept less than perfect? Why should you be careful?

The process relies on the availability of the web and on the speed of your connection. If, after having changed a file at home, you go to the office, turn on your computer and try to open and work on this very file without waiting for the update to be done, you’d simply be working on an older version without even knowing it! Worse — once done working on this old, “wrong” version, the synchronisation process will overwrite the very first one you worked on at home, thus wasting some of your data for good and forever. The truth is that synchronisation doesn’t always work as you expect it, though in theory it should.

Google, especially gmail, Samsung and countless networks propose to synchronise all your data — mainly your contacts list (guess why) — across networks and computers, telling you it’s a great way to have it backed up and available everywhere. In reality, and unless you know exactly what you’re doing and give time to the networks to refresh the files, you may end up with either redundant information, or worse, with data loss.

I’m living happily with one of the cloud’s drive services. This is only because I developed some good working habits after having first experienced the pain of seeing old versions of my files overwrite and destroy new versions. The primary precaution I now always exert consists, whenever I turn on a computer, to wait till synchronisation with my data in the cloud is done on this very computer. This sounds plain and simple but it is not always the case, for there isn’t necessarily an apparent indication on your screen that the operation has been done or was successful.

This is particularly true if your Internet connection is down. You may start your computer, launch an application and a document to work on, without first noticing that you have no Internet at all and that you are actually working on the non-updated version of the document, that is the one previously stored on your local hard disk.

But again, data and files synchronisation across the cloud is a fantastic tool when handled properly and with care. In many cases it has saved the life of those who lost all the information on their smartphone because of an incident and were able toretrieve it all afterwards precisely because it had been synchronised (i.e. copied, backed up) in the cloud before the incident.

Moreover, if your data is synchronised between more than two devices and you happen to experience file loss on two of them because of a synchronisation error or mishap, you can always go to the third device for example, start it offline (i.e. with Internet off), and retrieve the lost file(s) from there before it has the chance to connect to the Internet and do the synchronisation you donít want to do. Et voilà. 

Data synchronisation? Yes, by all means. But do it right and carefully.