User Case

"I'm using Cloud Sync to back up my Google Drive to my NAS. It's been supposedly syncing for months. However, upon closer inspection, I've noticed that not all the files and subfolders from Google Drive are present on the NAS backup.

Some present files are older or newer than the missing ones, and vice versa. It doesn't seem like the syncing problem started or stopped at a particular point in time. Additionally, there's no clear correlation between the files and folders I own versus those shared with me; some of both are missing."

Why is Synology Cloud Sync Not Syncing All Files?

Synology Cloud Sync Not Working
Synology Cloud Sync Not Working

Several factors could contribute to Cloud Sync not syncing all files on Synology. Let's see how they differ from each other:

  • Insufficient Cloud Storage Quota: If your cloud storage account has insufficient space, the sync process might fail to complete successfully. So, you have to get more cloud space to ensure you have enough storage available in your cloud account to accommodate all the files you want to sync.
  • Network Connectivity Issues: Stable internet connectivity is vital for the smooth functioning of Cloud Sync. If your network connection is weak or unstable, it can interrupt the sync process and lead to incomplete synchronization.
  • File Size Limitations: Certain cloud storage providers impose file size limitations. If you're trying to sync files that exceed these limitations, the sync process may halt or omit those large files.
  • File Name or Format Conflicts: Sometimes, certain characters or file formats in the filenames can lead to conflicts during the sync process. These conflicts can prevent specific files from syncing.
  • Synology Cloud Sync Configuration Errors: Incorrect configuration settings in Synology Cloud Sync can also cause sync issues. It's essential to review your settings to ensure they align with your cloud storage preferences.

Troubleshooting Synology Cloud Sync Not Syncing All Files

Synology Cloud Sync Cannot Sync All Files
Synology Cloud Sync Cannot Sync All Files

Now that we've identified the potential causes, let's explore troubleshooting steps to resolve the sync issue:

Way 1: Check Cloud Storage Quota

Verify the available storage space in your cloud storage account. If it's nearing capacity, consider freeing up space or upgrading to a larger storage plan.

Way 2: Ensure Stable Network Connection

To avoid network-related sync issues, ensure that your Synology NAS has a stable and reliable internet connection. If necessary, consider using a wired connection for better stability to get rid of the Synology Cloud Sync suspend trouble.

Way 3: Verify File Size Compatibility

Check if the files you're trying to sync comply with the file size limitations set by your cloud storage provider. If some files are too large, consider compressing or dividing them into smaller parts.

Way 4: Resolve File Name Conflicts

Review your file names for any conflicting characters or formats. Rename files if necessary to avoid potential conflicts during the sync process.

Way 5: Review Synology Cloud Sync Settings

Double-check your Synology Cloud Sync settings to ensure they align with your cloud storage preferences. Adjust any settings as needed to facilitate a smooth sync process.

Best Way to Sync Google Drive with Synology via MultCloud

If the above solutions can’t handle the Synology Cloud Sync not syncing all files situation, you can try to use MultCloud Cloud Sync as an alternative and it would be better:

  • MultCloud doesn't use your bandwidth to transfer files, so you won’t be stuck in a weak network connection issue.
  • MultCloud can automatically rename the files that contain special characters and generate a script file. So, you can also avoid the conflicted file name problem.
  • MultCloud sync process can also go bidirectional and you can use the Two-way Sync mode.
  • You can also schedule the sync task and make it run in real time.
  • Since MultCloud is a cloud management service, it can be used to sync Synology with SharePoint Online, OneDrive, Dropbox, and other clouds.

Step 1: Click “Get started for free” on the home page of the MultCloud web to get a new account.

Step 2: Add Google Drive and Synology NAS to MultCloud by clicking “Add Cloud” and their icons. Also, log in to your accounts in the pop-up windows.

Add Google Drive and NAS
Add Google Drive and NAS

Step 3: Click “Cloud Sync” and choose Google Drive in the FROM box and NAS in the TO box. Finally, tap on the “Sync Now” button to start the file syncing task.

Sync Google Drive with NAS
Sync Google Drive to NAS


  • You can automate the sync task with the Schedule feature. What you need to do is choose an exact time and save this setting. Then the task will run at the appointed time automatically.
  • If you only want to sync some files like documents, photos, videos, or others, you can use the Filter feature to pick out these files at once instead of selecting manually.
  • If you have many large files to sync, the 5GB of free traffic may not meet your need and you can buy a paid plan to get more traffic.
MultCloud Cloud Sync Filter
MultCloud Cloud Sync Filter


Like any software, Synology Cloud Sync may encounter occasional issues. In this guide, we've discussed the common problem of "Synology Cloud Sync not syncing all files" and provided troubleshooting solutions to overcome it.

Besides, the post provides a brand-new way for you to sync Google Drive with Synology and that is using MultCloud Cloud Sync. You may try it as an alternative to Synology Cloud Sync. There are more great functions on MultCloud and more issue solutions can be solved with them. If you want to backup Gmail to Synology NAS, just go with MultCloud!

Why is Synology Cloud Sync not working properly?
Synology Cloud Sync might encounter issues due to various factors, including insufficient cloud storage, network connectivity problems, file size limitations, file name conflicts, or misconfigured settings.
How can I fix the sync problem on my Synology NAS?
You can troubleshoot the issue by checking your cloud storage quota, ensuring a stable network connection, verifying file size compatibility, resolving file name conflicts, and reviewing your Synology Cloud Sync settings.
Does Synology Cloud Sync support all cloud storage platforms?
Yes, Synology Cloud Sync supports multiple cloud storage providers like Dropbox, Google Drive, OneDrive, and more, allowing you to sync files across different platforms seamlessly.
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