Delete a file on one laptop, and a sync service deletes it on every other laptop and in the cloud within moments. That is not a fault. It is exactly what sync is for.
Sync and backup both make copies, so they get confused. They make copies for opposite reasons. Sync keeps everything the same. Backup keeps things different: a record of how your files looked yesterday, last week and last quarter.
What sync is built to do
A sync tool watches a folder. When a file changes on one device, it sends that change to the cloud and then to every other device that shares the folder. The goal is one current version, everywhere, as fast as possible.
That makes sync very good at:
- working on the same files from the office, from home and from a job site
- sharing a folder with a colleague or a client without emailing attachments
- setting up a new laptop quickly, because the files pull down on their own
What sync passes along, it passes along faithfully. A deletion is a change. So is a rename, a file saved over with the wrong version, or a folder of files encrypted by ransomware. Sync sends each of them everywhere it sends everything else.
CISA’s #StopRansomware Guide warns that “many ransomware variants attempt to find and subsequently delete or encrypt accessible backups.” A synced folder is about as accessible as a copy can be: it is open on every device, under every user’s login.
What backup is built to do
A backup copies data to a separate place on a schedule and keeps each copy as a version. New copies do not overwrite old ones. When something goes wrong, you pick a point in time from before the problem and restore from it.
Three properties make a backup different from a sync copy:
- It keeps history. Versions are kept for a set retention period, not only the newest state.
- It runs one way. Changes on your laptop flow into the backup. Nothing flows back unless someone restores on purpose.
- It sits apart. A good backup lives under different credentials, so a person or a program that can damage your live files cannot reach it.
The backup and recovery glossary has short definitions of versioning, retention and the other terms used on this page.
Version history has limits
Most business sync tools keep version history and a deleted-files area. That covers many everyday mistakes. You save over a spreadsheet, and you open Tuesday’s version instead.
It falls short in three ways:
- It has a time limit. History is kept for a set number of days, then it is gone. A mistake found after the window is permanent.
- It works best file by file. Rolling a whole shared folder back to a moment last week can be slow or impossible, depending on the tool.
- It lives in the same account. Anyone with admin rights, or a stolen admin password, can purge it. If the account is closed, the history goes with it.
So version history is a convenience. It is not a separate copy, and the 3-2-1 backup rule does not count it as one.
Side by side
| Question | Sync | Backup |
|---|---|---|
| Purpose | The same files everywhere, now | Earlier versions, recoverable later |
| A deleted file | Deleted everywhere | Still in older versions |
| Files encrypted by ransomware | Uploaded and spread | Clean versions kept from before |
| Direction | Two-way | One-way; restores are deliberate |
| History | A limited window, same account | A set retention, separate storage |
| Best at | Collaboration and remote work | Recovery after mistakes and failures |
Neither column is better. They answer different questions, and an office that has only one of them has a gap.
What backup cannot do
To be fair to sync, backup is a poor substitute for it. A backup is not a place to work. Nobody edits files inside it, shares a link from it or opens it on a phone at a job site.
Restores are also deliberate. Getting a file back means asking for it, choosing a version and putting it somewhere. That takes minutes for one file and longer for a large folder. Sync, by contrast, is instant and invisible.
So the goal is not to replace sync with backup. It is to make sure that anything sync can destroy, a backup can bring back.
Example: a cleanup that synced everywhere
Picture a nine-person marketing agency that keeps all client work in one synced team folder. A contractor finishing a project tidies up what they think is their own copy of a client folder, and deletes about 4,000 files.
The deletion reaches every laptop within minutes. Nobody notices for three weeks, until the client asks for the original artwork. By then the sync tool’s deleted-files area may have emptied, depending on its window, and the files exist nowhere else.
With a separate backup of that folder, the fix is dull. Pick a version from the day before the cleanup, restore the folder to a new location, check it, then move it back into the shared folder. With sync alone, the agency is asking the client for copies of its own work.
Notice that nothing malicious happened. One person made a reasonable mistake, and sync did its job.
How to run both without gaps
For most small businesses the answer is not to choose. Use sync for collaboration, and back up what sync holds. Four practical rules:
- Back up the sync store itself. Shared folders live in the sync service’s cloud. Back them up there, on their own schedule, so a deletion that reaches every device still has an older version somewhere else.
- Back up laptops for what sync misses. Desktops, downloads, local app data and files saved outside the synced folder are common gaps. The Workstation Backup plan copies file changes every hour a laptop is online and keeps 90 days of versions.
- Use different credentials. The account that runs sync should not be able to delete the backup.
- Restore from both, once a quarter. One file from sync history, one folder from the backup. If either fails, you found out on a quiet day.
This is how the Team Sync plan is built: managed sync with permissions and shared folders, 180 days of version history, and a separate nightly backup of the sync store underneath. A deletion that syncs everywhere can still be restored from the nightly copy taken before it happened. The plan starts from $9 per user per month (indicative).
If you are weighing the whole picture, the file sync and sharing service page explains how sync, permissions and backup fit together.
Where people get caught out
A few patterns come up again and again when an office relies on sync alone:
- The laptop that never synced. Someone saves to the desktop instead of the shared folder for months. The laptop fails, and the work was never anywhere else.
- The departing user. An account is removed to save a license, and the files only that person owned go with it.
- The conflict copy. Two people edit the same file offline. Sync keeps both, renamed, and someone deletes the wrong one. Why sync loses files covers this in detail.
- The fast spread. One infected laptop encrypts its synced folder, and every other device receives the encrypted versions as ordinary updates.
Each of these is a normal day for a sync tool. Each one is a restore job for a backup.
Questions to ask about your setup
- If someone deletes a shared folder today, how many days do we have to notice?
- Who can empty the deleted-files area or purge version history?
- Is there a copy of the shared folders outside the sync account?
- Which folders on each laptop are not synced, and are those backed up?
- When did anyone last restore a whole folder, rather than one file?
If an answer is “we don’t know,” that is a fine place to start.
Check your own folders
The free backup check covers sync as well as backup. In 45 minutes, remotely, we look at what is synced, what is backed up and where the two overlap, then run one test restore with you. You get a written page of findings to keep. Book a free backup check if that would help.
