Backup is undoubtedly important for most people with digital data. However, individuals often risk data loss by using dangerous strategies. Here, I will show a few false (and dangerous) notions that people often hold for their data backup.
“External Hard Drives are Enough for Backup”
While you may be well aware of the possibility of external hard drive breaking down and make backups on multiple external hard drives, but it is certainly not enough. Usually, when you make backup on external hard drives or optical discs, you typically store them in your home or in the office. But some extreme situations can happen: fire, theft, earthquake, or some magnets that break all the drives. It is usually considered much safer to make remote backup along with these external drives. To make remote backup, you can either use a simple method such as uploading files to cloud storage websites like Dropbox or OneDrive, or use a more sophisticated approach to make frequent backup easier: use incremental backup software such as Areca Backup or Back In Time along with a backup virtual private server (VPS) such as Backupsy and Time4VPS.
“File Synchronization Software is a Reliable Backup Tool”
Many people heavily rely on file synchronization software such as Dropbox, Google Drive, Bit Torrent Sync, Syncthing, etc. to back up. I would say they aren’t really reliable: the data can be lost forever in many circumstances. For example, a software bug, or a corruption of your local disk, may well affect the remote copy that you may even not know for a long time. While you can still use these software as convenient “backup” tools, my recommendation is to make sure you make snapshots: you can always go back if you found a certain file is corrupted. In order for it to be easier to make snapshots, you may wanna try some incremental backup software such as Areca Backup on Windows, Time Machine on Mac OS X or Back In Time on GNU/Linux.
“No Need to Back up Things on the Internet”
Anything on the Internet may disappear someday—even this blog post you are reading. People remove articles, videos and other contents on the Internet all the time for various reasons: commercial purpose (e.g., free contents become paid), copyright infringement, or the content owner simply goes bankrupted. If you really don’t want to lose access to some Internet contents, you probably want to make a local copy and make proper backup copies. For example, for YouTube videos, you can download them via sites like savefrom.net or a software like youtube-dl; for an article, you can save the web page as a PDF file; for an image, you can save them to your local disk by right clicking them in your browser.