A friend called me last spring in a genuine panic. His two-bay Synology had been humming along for four years, both drives mirrored, and one morning it greeted him with a solid amber light and no shares.
He was calm at first. He had a backup, after all. Except the backup was a second folder on the same NAS.
That conversation is the reason I wrote this. The failures I see are almost never exotic. They are the same handful of comfortable assumptions, made by smart people, repeated across thousands of home setups. Here are the ones that cost people their photos and how to correct each before you are the one staring at an amber light.
Mistake 1: Treating RAID as a backup
This is the big one, so it goes first. RAID keeps your NAS running when a single drive dies. It does not protect your files from anything else.
Ransomware encrypts a RAID array just as happily as a single disk. So does an accidental delete, a corrupted volume, a bad firmware update, or a lightning strike that fries the whole chassis. RAID is about uptime, not safety.
The distinction has a name worth learning. RAID gives you redundancy; a backup gives you a separate, independent copy you can fall back on. Synology says it plainly in their own documentation, and it is worth reading their short explainer on what RAID actually does.
Mistake 2: Backing up to the same NAS
My friend's setup was this exact trap. A scheduled job copied Shares to a Backup folder on the same box, and it felt responsible because a task was clearly running every night.
The problem is that both copies share a fate. A dead power supply, a stolen unit, a flooded basement, or an encryption attack takes both at once.
A backup has to be independent. That means a different physical device, ideally in a different building or in the cloud. Copying between two folders, two volumes, or even two drives inside the same chassis does not clear that bar.
Mistake 3: Ignoring the 3-2-1 rule
The old 3-2-1 rule survives because it works. Three copies of your data, on two different types of media, with one copy kept offsite.
For a home user that usually looks like this: the live copy on your NAS, a local copy on an external USB drive or a second NAS, and an offsite copy in a cloud service. Backblaze has a clear write-up of the 3-2-1 backup strategy if you want the full reasoning.
| Copy | Where it lives | Protects against |
|---|---|---|
| Primary | NAS volume | Nothing, it is the working copy |
| Local backup | External USB or second NAS | Drive failure, accidental delete |
| Offsite backup | Cloud or friend's house | Fire, theft, flood, ransomware |
You do not need enterprise gear for this. A 5TB USB drive runs about 110 dollars, and cloud backup for a home volume often lands between 5 and 15 dollars a month depending on size.
Mistake 4: Never testing a restore
A backup you have never restored from is a hope, not a plan. This is the mistake I fell into myself, years ago, before I knew better.
I had a nightly job running for eight months. When I finally needed a file back, the job had been silently failing since a permissions change, and the most recent good copy was from the previous autumn.
Test restores on a schedule. Once a quarter, pull a real file from your backup onto a different machine and open it. Confirm it is the right version and that it actually opens.
Mistake 5: No versioning, so bad data overwrites good
Plain mirroring has a nasty edge case. If a file gets corrupted or encrypted on your NAS, the next sync faithfully copies that damage over your good backup.
Now both copies are ruined, and your backup did exactly what you told it to.
Versioning fixes this by keeping multiple older copies. Synology Hyper Backup, for example, can retain daily and weekly versions so you can roll back to before the corruption. Keep at least 30 days of versions if your storage allows it.
Mistake 6: Set it and forget it, with no alerts
Backups fail quietly. A full destination, an expired cloud token, a drive that dropped offline, none of these announce themselves unless you tell the NAS to shout.
Turn on email or push notifications for backup job results. On Synology this lives under Control Panel and Notification; on QNAP it is in the Notification Center.
You want a message on both success and failure at first. After a month of green results, you can trim it back to failures only, once you trust the alerts are actually arriving.
Mistake 7: Forgetting the NAS configuration itself
People back up their files and forget the box that serves them. When a NAS dies, rebuilding users, shared folders, permissions, and app settings from memory is miserable.
Most systems can export their config. On Synology it is Control Panel, Update and Restore, Configuration Backup. Save that export alongside your data backups so a hardware swap becomes an afternoon instead of a lost weekend.
Mistake 8: Assuming cloud sync equals backup
Dropbox, Google Drive, and OneDrive sync folders are not backups. Sync means changes propagate in both directions, so a delete or an encryption on one end reaches the other.
Real backup software keeps history and does not blindly mirror deletions. If your offsite strategy is a sync folder, add a true backup target with versioning next to it.
A short checklist to fix all of this
- Confirm you have at least one copy on a separate physical device
- Add an offsite copy, cloud or a drive at another location
- Enable versioning with at least 30 days of history
- Turn on backup job notifications for failures
- Export your NAS configuration and store it with the data
- Schedule a quarterly restore test and actually do it
Where to point your first hour
If all of this feels like a lot, pick the two that matter most and start there. Get one independent copy of your irreplaceable files off the NAS today, then run a single restore test this week to prove it works.
Everything else on the list is refinement. Those two steps alone move you from the group of people who lose their photos to the group who tell the story afterward with relief instead of regret.
My friend recovered most of his data, by the way, through a paid recovery service and a lot of luck. He now runs a second NAS at his sister's house. He also tells this story more often than I do.
Frequently asked questions
Isn't a mirrored two-bay NAS already a backup?
No. A mirror (RAID 1) keeps you running if one of the two drives dies, but both drives share the same enclosure, power supply, and file system. An accidental delete, ransomware, a failed volume, or a stolen unit takes both copies at once. You still need at least one independent copy on a separate device.
How often should I test a restore?
Once a quarter is a sensible rhythm for home use. Pull one real file from the backup onto a different computer, open it, and confirm it is the correct version. This ten-minute check catches silent failures, expired tokens, and permission problems long before you actually need the data.
What is the cheapest way to add an offsite copy?
For most home users a cloud backup service is the easiest offsite option, often 5 to 15 dollars a month depending on volume size. If you prefer no monthly fee, rotate an encrypted external USB drive to a friend's or family member's house every couple of weeks.
Does cloud sync like Dropbox or Google Drive count as a backup?
Not on its own. Sync propagates changes in both directions, so a deletion or a ransomware encryption on your NAS can reach the cloud copy too. Use dedicated backup software that keeps version history rather than relying on a sync folder as your safety net.
How many versions should I keep?
Aim for at least 30 days of versions if your backup destination has room. That window is usually enough to notice corruption or an accidental change and roll back to a clean copy. Longer retention is better if you can afford the storage, especially for documents and photos.
