The hardware reason USB sticks make terrible backups
When a relative recently told me that he backs up his files on a simple USB stick, I was amazed. And yes, it was just that one; no 3-2-1 rule here. And yes, of course, some of these files were important.
It got me thinking about how many of us have probably done the same thing. I know I’ve kept documents on various USB drives, which I’ve since lost or seen die over time. We’ve all made this mistake, but let’s finally stop making it: USB drives are just about the worst thing you can use as a backup destination.
Flash drives are not designed for long-term storage
They are convenient, but not so secure.
At a time when SSDs cost a fortune and, well, basically All costs a fortune, I totally take shortcuts with USB drives. All things considered, their price per gigabyte isn’t that great… for now. But there is also a good reason for this.
They just weren’t made for serious backups.
A so-called “serious backup” has only one task. It should keep your files safe and sound for the time needed between the time you store them and the time you think about saving them. Flash drives are not the best option for this, however.
Most USB drives use NAND flash memory, which stores bits as an electrical charge. This charge leaks slowly over time and the margin for error gets worse with heat and wear from previous writes. Note: This is the same thing that powers SSDs, and is also why it’s not a good idea to leave your SSD in a drawer for hours.
Obviously, NAND flash can be useful for storage, given that SSDs perform very well (although some fail even at 100% health). But USB drives are optimized to be cheap and not durable. They are not expected to last for years and years while maintaining perfect data integrity.
They often have basic controllers, limited ECC (error correction), and very few meaningful health reports. As such, you may not receive a big red warning when your backup is about to disappear forever.
When a USB Drive Fails, It Fails in the Worst Way
It’s not one of those things that comes out with a whimper.
If there is a perfect environment for storing your data, USB drives live in the exact opposite. They are plugged in and out frequently, then thrown into a bag or drawer and left to rot. And yet we still ask them to do the most demanding thing possible, which is a large write of various files.
Even if nothing fails, the margin for error is still pretty lousy. Many people format drives as exFAT for convenience, and exFAT and FAT style file systems are much less forgiving when something interrupts a write. One brief glitch and you may end up with a drive that still appears, but the folder structure is mangled, the files are odd sizes, or the directory appears empty even though the data is technically there.
Then there’s the fact that cheap USB drives can become unstable with prolonged writes. And they can overheat, slow down, stall, and trigger timeouts. These things often have a bad time and your files are there to share all their problems.
The problem is that if you never check these files, you may come away thinking that your USB drive is working just fine, even though under the hood it really isn’t. Data corruption can creep in without your knowledge, meaning you may not be ready to make another backup.
A true backup plan is a system, not a single device
When you need a backup plan for your backup plan.
That’s part of why I was so surprised when my loved one told me that a USB drive was his entire backup. I was proud in a way, because well, it’s better than nothing, but on the other hand… it’s risky.
A true backup plan is a repeatable system that doesn’t hope for the best. Instead, it sort of assumes that something is going to go wrong. If your files are important, unfortunately you have to expect the worst at all times.
This is why the 3-2-1 save rule remains relevant. You should keep three copies of your data, on two different types of storage, including one copy offsite. In fact, it basically means somewhere other than your home. More often than not these days it will just be cloud storage.
Finally, do a spot check of a few files, especially the important ones. Don’t just copy them, but run them and see that everything is fine. Remember that a USB drive left to its own devices can die or lose data. It is therefore important to repeat these checks from time to time.
If you insist on using USB sticks, at least do so
I’m not saying “never”, I’m just saying “wait”.
Listen, I understand. USB sticks are super convenient. I have more than I can count.
But don’t trust them as if they were a real external drive. Use them for your convenience and only for your convenience; don’t even make it something you use for backups.
Whether it’s a hard drive, an external SSD, or a fast internal NVMe, anything is better than a USB drive, and that’s where your files should reside.
And if you take a USB drive away from home, encrypt it. Losing a small drive can happen to anyone, but you don’t want to have to panic about who finds it and what they will do with your files (been there, done that).
