Quick reminder - BACKUP means COPIES of your data.
I sometimes see people move a large collection of photos or documents to an external drive to make space on their computer, and then call that a backup.
It is not.
Any drive or device or service can fail, and will some day, and if you have something important that is only in one place, it will be lost when that thing fails. To qualify as a backup, it must exist in more than one place.
Ideally, it should be more than that, and a common phrase to summarize a great backup strategy is the 3-2-1 rule.
3-2-1 Backups
The 3-2-1 backup rule basically means this:
- 3 Copies of Data – Maintain three copies of data — the original, and at least two copies.
- 2 Different Media – Use two different media types for storage - external hard drive, USB memory stick, cloud backup, NAS, etc.. It’s your decision as to which storage medium will contain the original data and which will contain any of the additional copies.
- 1 Copy Offsite – Keep one copy offsite to prevent the possibility of data loss due to a site-specific failure. If your two copies are on external drive or USB stick, keep one of them elsewhere. If one or more of your backups are to the cloud (online), that counts as offsite.
Additionally, it can be very valuable for at least one of the backups to be versioned. That basically means that you can go back to a file or folder the way it was 2 days ago, or 2 weeks ago, not just the latest version you backed up. This is critical to prevent loss due to ransomware, so that if all your data has been changed to lock you out (pending your payment to the hacker), that you can go back to a backup from an earlier date and retrieve all your data.
Admittedly backup can be a complex subject, but let's start simple.
If anything important is in only one place, it's at risk. Please make a copy of it somewhere else, as the most basic starting point! You can follow up with fancy backup strategies later, but lets start with just making sure you have at least one simple backup.