How to Sync Your NAS with Cloud Storage Without Paying Twice
You’ve got a NAS at home protecting your files locally, and you’re paying for cloud storage to keep an offsite copy. Smart move. But if you’re not careful about how you sync between the two, you’ll end up storing (and paying for) way more cloud data than you actually need. Duplicate system files, temporary folders, old downloads you forgot to delete: all of it eating into your monthly bill.
The good part is that both Synology and QNAP ship with built-in tools that let you sync selectively and control bandwidth so your internet connection doesn’t grind to a halt. Here’s how to set it all up properly.
Synology Cloud Sync: Setup and Selective Sync
Synology’s Cloud Sync package (available free in Package Center) connects your NAS to over 30 cloud providers, including Google Drive, Dropbox, Amazon S3, Backblaze B2, and Microsoft OneDrive. It’s one of the main reasons people pick Synology for home and small office use.
To get started, open Package Center, install Cloud Sync, and link your cloud account. During setup, you’ll choose a local folder on your NAS and a corresponding cloud folder. Here’s where most people go wrong: they sync their entire shared folder. Don’t do that.
Pick Only What Matters
Use the Selective Sync option to choose specific subfolders. For most home users, that means syncing your Photos, Documents, and critical project folders while skipping things like your media library (which can be re-downloaded), software installers, and temporary files. If you’ve got 4TB on your NAS but only 500GB of truly irreplaceable data, there’s no reason to pay for 4TB of cloud storage.
You can also set file size filters and file type filters. For example, exclude .tmp, .ds_store, and Thumbs.db files. These add up surprisingly fast and serve zero purpose in the cloud.
If you’re still weighing whether cloud sync is worth the ongoing cost alongside your local NAS, our cloud backup vs. local NAS cost comparison breaks down the real numbers for 2026.
For a reliable two-bay unit that handles Cloud Sync without breaking a sweat, the Synology DS224+ is an excellent choice. It has enough RAM and CPU power to run sync tasks in the background while still serving files to your network.
Synology DS224+ NAS
A great two-bay NAS with built-in Cloud Sync support and enough horsepower for background sync tasks.
QNAP Hybrid Backup Sync: The Same Idea, Different Interface
QNAP bundles its cloud sync features inside Hybrid Backup Sync (HBS 3), which you can install from the App Center. HBS 3 combines backup, restore, and sync into one tool. It supports Google Cloud Storage, Azure, AWS S3, Backblaze B2, Wasabi, and more.
Create a new Sync Job, pick your cloud destination, and then use the Filter Settings to include or exclude specific file types, folder names, or file sizes. QNAP also lets you set a sync direction: one-way upload (NAS to cloud), one-way download (cloud to NAS), or two-way. For a pure backup scenario, one-way upload keeps things simple and prevents accidental deletions in the cloud from wiping your local copies.
A QNAP unit like the QNAP TS-264 handles HBS 3 well and offers NVMe caching slots if you want faster sync performance. Just starting out with NAS hardware? Our NAS setup guide for beginners covers the basics before you start layering on cloud sync.
QNAP TS-264 NAS
Solid mid-range NAS with NVMe caching support and QNAP’s Hybrid Backup Sync built in.
Bandwidth Management: Don’t Kill Your Internet
An initial cloud sync of hundreds of gigabytes will saturate your upload bandwidth for days if you let it run unchecked. Both Synology and QNAP offer bandwidth scheduling, and you should absolutely use it.
In Synology Cloud Sync, go to the task’s settings and set an upload speed limit. You can schedule full-speed uploads for nighttime (say, midnight to 6 AM) and throttle to 1-2 MB/s during the day. QNAP’s HBS 3 has a nearly identical scheduling feature under the Bandwidth Limit tab.
A practical approach: run your initial sync overnight for a week or two, depending on how much data you have. After the initial upload finishes, incremental syncs are tiny and won’t impact your connection noticeably. Once you’ve got automated backups running to your NAS, the cloud sync picks up new and changed files automatically without you thinking about it.
Also, if your NAS drives are aging and sync performance seems slow, the bottleneck might be your hardware. Upgrading to faster NAS drives or adding an SSD cache can help. Check our guide on SSD vs. HDD differences to see if a cache drive makes sense for your setup.
FAQ
Can I sync my NAS to multiple cloud providers at the same time?
Yes. Both Synology Cloud Sync and QNAP HBS 3 support multiple simultaneous sync tasks to different providers. You could sync your photos to Google Drive and your documents to Backblaze B2, for example. Just be mindful of your upload bandwidth if you’re running several tasks concurrently.
Will cloud sync protect me from ransomware?
Not by itself. If ransomware encrypts files on your NAS, those encrypted files will sync to the cloud and overwrite the good copies. To protect against this, enable file versioning on your cloud provider (Google Drive and Backblaze B2 both support it). This lets you roll back to a previous, clean version. For true protection, pair cloud sync with a separate, versioned backup, not just a mirror sync.
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James Kennedy is a writer and product researcher at Drives Hero with a background in IT administration and consulting. He has hands-on experience with storage, networking, and system performance, and regularly improves and optimizes his home networking setup.
