Back up important files and test a restore
Choose what matters, keep a separate copy and make sure you can actually retrieve a file from it.
Follow the method ↓
The answer in 30 seconds
A backup is useful only if it contains the right files and can be restored when the original device is unavailable. Synchronisation and backup solve related but different problems.
List the files you would struggle to replace, copy them to a separate location on a schedule you can maintain, then restore one sample file to check the result.
Examples to adapt
Keep the originals and a second copy outside the phone; test opening a few pictures and videos.
Check whether your organisation already provides managed backup before making personal copies of sensitive files.
Restore a small sample first, then confirm that documents, dates and formats survived the transfer.
Follow the method
- 1Identify essential files
Include photos, records, projects and any export needed to leave a service.
- 2Choose a separate destination
An external drive or suitable cloud backup can protect against loss of the original device.
- 3Set a repeatable schedule
Match the interval to how often the files change and what you could afford to recreate.
- 4Protect the backup
Control access to the drive or account and disconnect removable media when the copy is complete.
- 5Test a restore
Retrieve a sample file, open it and check whether its content is complete before relying on the system.
A closer look
Define coverage before counting copies
Fictional example: you want to recover documents, photographs and settings after an incident. Check the three groups separately.
| Element | Observation | Decision |
|---|---|---|
| Documents | Included in the planned copy | Test a representative document |
| Photographs | Folder outside the selected scope | Add it to the plan or identify another copy |
| Settings | Restoration method unknown | Document the gap before calling the plan complete |
Two copies of one subset do not cover files left outside it. Scope and restoration testing are separate checks.
Does a “completed” message prove everything is recoverable?
It describes the operation performed. Review its coverage, then restore a sample to a separate location without overwriting originals.
A checklist to keep
Use these checks to record what you found. The grid supports a decision; it does not make one for you.
| Check | What to examine | Action |
|---|---|---|
| Scope | Which files would be hard to replace? | List |
| Location | Is the copy separate from the original device? | Choose |
| Frequency | When was the last successful copy? | Schedule |
| Access | Who can open or delete the backup? | Protect |
| Restore | Did a sample file open correctly? | Test |
Read the checklist directly in the table.
What to check
A copy in another folder of the same device does not cover device loss.
A synced deletion may spread to connected devices; confirm whether version history or backup is available.
A backup that has never been restored remains unproven.
Common questions
How many copies do I need?
The right number depends on what you could lose. A separate backup is the minimum useful step; additional independent copies improve resilience.
Can I rely on a cloud folder alone?
Check whether it keeps deleted files and earlier versions, and whether you can export and restore them without the original device.
Sources and documentation
Documentation consulted on . Examples are illustrative; interfaces and results may change.
Apply this method to a wider task
Restoring a backup: which files should you retain?
The newest file is not always enough to restore your data. The backup type determines which components recovery needs.
- Identify the backup set
- Locate dependencies
- Open a restored copy
| Situation | What changes | Useful check |
|---|---|---|
| Full | Copies all selected data. | Check the scope and excluded folders. |
| Incremental | Changes since the previous backup. | Retain the starting full backup and required increments in order. |
| Differential | Changes since the latest full backup. | Retain the starting full backup and chosen differential. |
Test a non-sensitive file in a separate folder without overwriting the original. Record the recovered version and errors. Disconnect the medium after use: a connected copy can also be affected by an incident.
Documentation : Cybermalveillance.gouv.fr — Sauvegardes ↗ · · Read the reference record →