Cloud Sync is the DSM app that connects external cloud providers to your storageDRIVE. Useful for: migrating away from Google Drive/Dropbox/OneDrive, hybrid setups (two clouds in parallel), extra backup layers. Here’s what works and how. (iCloud is the exception — more on that below.)
Starting Cloud Sync
In the DSM main menu → Cloud Sync.
On first launch the app is empty — you create your first Cloud Sync task.
Which external clouds work
Currently supported providers:
- Google Drive
- Microsoft OneDrive (personal and Business)
- Dropbox (personal and Business)
- Box.com
- Amazon Drive (limited — Amazon has partially shut down its consumer API)
- Backblaze B2
- Amazon S3 (and S3-compatible: Wasabi, Storj, etc.)
- Microsoft Azure
- Google Cloud Storage
- WebDAV (to any WebDAV server)
- Synology C2 (Synology’s own cloud)
- Hidrive, MagentaCloud, Hubic, and more
Full list: 25+ providers, depending on the DSM version.
Sync modes
When creating a sync task you choose:
Bidirectional
Changes sync in both directions.
Use case: you have files in Google Drive AND in storageDRIVE — both should always match.
Careful: on conflicts, Cloud Sync has to decide. Conflict files can appear.
Local → remote only
storageDRIVE as master, changes get pushed to Google Drive.
Use case: you work in storageDRIVE but want an extra copy in Google Drive for emergencies.
Remote → local only
The external cloud as master, storageDRIVE only receives.
Use case: migration — you have lots of files in Dropbox and want to bring them to storageDRIVE without changing anything in Dropbox.
Example setup: migrating from Google Drive
- Open Cloud Sync → + New sync task
- Select Google Drive
- Browser opens → Google login via OAuth → grant permissions
- Sync mode: remote → local only (safe: Google Drive stays untouched)
- Source folder on Google Drive:
My Drive(or a specific folder) - Destination folder in storageDRIVE: e.g.
/Migration-Google-Drive - File filter: all files or only certain types
- Encryption in transit: enable (default)
- Save → sync starts
The first sync can take a while (1 GB ~10 min, 100 GB ~many hours). Cloud Sync runs in the background, you don’t need to babysit it.
Pitfalls
Google Drive: native Google files
.gdoc, .gsheet, .gslides aren’t real files — just links to Google’s editors. Cloud Sync can’t transfer them 1:1.
The fix:
- In Google Drive before migrating: right-click → Download → gets exported as
.docx/.xlsx/.pptx - Or a sync task with format conversion: Cloud Sync has an option to convert native formats to MS Office formats during sync
iCloud doesn’t work via Cloud Sync
Apple offers no third-party sync API for iCloud — iCloud is missing from Cloud Sync’s provider list, and neither Synology nor we can change that.
The path for iCloud migration: download the data from iCloud locally (a Mac with a full iCloud Drive download, or a privacy.apple.com export), then upload it to storageDRIVE via the Drive client or WebDAV. For large collections: send us a drive and we’ll upload it free of charge over our 10 Gbit connection.
Bandwidth
Cloud Sync consumes bandwidth — both at the external cloud and on our side. When migrating large amounts: the external cloud can trigger rate limits (Google Drive caps at ~750 GB/day).
In Cloud Sync: schedule / bandwidth limit is configurable.
Conflicts
With bidirectional sync and frequent edits: conflict files (file (conflict from Cloud Sync)) appear.
Our recommendation: don’t use bidirectional sync for active files. Better:
- One cloud as master for active work
- The other cloud as a backup mirror (one-directional)
Use cases
Hybrid setup
You use Google Workspace for work (Google Drive + Office) but want a private backup on storageDRIVE.
→ One-directional sync Google Drive → storageDRIVE, running nightly.
Migration with a safety net
You’re moving from Dropbox to storageDRIVE but want to keep Dropbox as backup.
→ Bidirectional sync for 3 months. After 3 months: storageDRIVE is master, switch the Dropbox sync to one-directional, later turn it off entirely.
S3 as off-site backup
You want Backblaze B2 as an off-site backup in addition to storageDRIVE.
→ Cloud Sync task storageDRIVE → B2, one-directional, daily.
Multi-cloud strategy
Important data in 3 clouds: storageDRIVE (primary), Google Drive (secondary), Backblaze B2 (cold storage).
→ Configure two Cloud Sync tasks. Watch the storage usage — cheap at Backblaze, expensive at Google.
Encryption in transit
Cloud Sync uses TLS for all connections — encryption in transit is the default.
Optional: encryption in the external cloud:
In the Cloud Sync task → enable Encrypt. Files are encrypted with AES-256 before being uploaded to the external cloud — the external provider only sees ciphertext.
Use case: backing up sensitive data to Google Drive without Google being able to read the content.
Trade-off: files in the external cloud are only readable again through Cloud Sync. If you open Google Drive directly in the browser, all you see are encrypted blobs.
Schedule
In the sync task → Schedule:
- Continuous (as soon as a change is detected)
- Scheduled (daily at time X)
- Manual (only on click)
Our recommendation: continuous for active sync relationships, scheduled for backup mirrors.
Pausing / deleting a sync task
Cloud Sync sidebar → right-click the sync task:
- Pause — sync stops, the configuration stays
- Delete — the sync configuration is gone, the files stay (on both sides)
- Re-authenticate connection — e.g. when the Google OAuth token has expired
Frequently asked questions
How fast is a migration from Google Drive? Depends on both sides. Typically 100–300 GB/day with default settings; it can be throttled via bandwidth limits.
What if the external cloud changes the password/OAuth? The sync errors out. You get a notification and have to re-authenticate.
Does Cloud Sync keep the file structure 1:1? Yes. The folder hierarchy is carried over.
What happens to file permissions / sharing? They aren’t transferred. Sharing links have to be recreated in the destination cloud.
Bidirectional sync between multiple devices — does that work? Yes, with caution. Frequent edits cause conflicts. Our recommendation: the Drive client for active working files; Cloud Sync for backup mirrors.
How do I see how much sync traffic has run so far? Cloud Sync shows per-task statistics with transferred bytes, file count, errors.
Does Cloud Sync work when the external cloud is encrypted? If the external cloud uses standard at-rest encryption (Google and Dropbox do): no problem. If the provider uses zero-knowledge E2EE (Tresorit, etc.): it doesn’t work — Cloud Sync can’t decrypt.
What’s next
First login to DSM
What you receive after ordering and how to log in to your storageDRIVE account for the first time.
Account and quota — how your storageDRIVE storage works
One plan, one user account, a fixed quota: what counts toward the quota, what happens when it's full, and how upgrades work.
File Station — the file manager in your browser
The classic file manager in DSM. Upload, download, creating folders, ZIP creation, previews, sharing links.
Mounting storageDRIVE as a drive (SMB)
How to connect your storageDRIVE via SMB as a drive — in the Mac Finder, Windows Explorer and as a mount on Linux. Step by step, including auto-mount and Time Machine.