Cloud Sync

With Cloud Sync, you can seamlessly sync and share files among your Synology NAS and multiple public cloud services, including:

  • Amazon Drive
  • Amazon S3 compatible cloud services (Amazon S3, hicloud S3 and SFR NAS Backup)
  • Backblaze B2
  • Baidu Cloud
  • Box
  • Dropbox (including Dropbox for Business)
  • Google Cloud Storage
  • Google Drive (including Google Drive for Work)
  • HiDrive
  • hubiC
  • Megafon Megadisk
  • Microsoft OneDrive (including OneDrive for Business)
  • Microsoft Azure
  • OpenStack Swift compatible cloud services (IBM SoftLayer, RackSpace, RackSpace UK)
  • WebDAV
  • Yandex Disk

Create New Connections

To sync files among your Synology NAS and public cloud services, you need to create connections on Cloud Sync to link to the service provider by using your user credentials.

To create a new connection:

  1. On the Cloud Sync user interface, click on the Create icon at the bottom-left corner to start the wizard.
  2. Choose one of the following public cloud services to sync files with and click Next.
    • Dropbox, Baidu Cloud, Google Drive, Box, OneDrive, Amazon Drive, Megafon Megadisk, HiDrive and hubiC: log in with your user credentials.
    • WebDAV: input the server address, your account and password. Server address should follow the formats specified below:
      • Input http or https URLs of the intended WebDAV server, with custom port number after the colon (optional), e.g. http://mywebdavserver.synology.me:5005 or https://mywebdavserver.synology.me:5006
      • Cloud Sync will connect to the server via http if the URL does not imply http or https.
      • If port number is not specified in the URL, Cloud Sync will access port 80 in http connections, and port 443 in https connections.
      • Path can be appended to the URL, e.g. https://mywebdavserver.synology.me:5006/webdav/folder
    • Yandex: input your account and password.
    • Google Cloud Storage: log in with your user credentials, then Project ID and Bucket name.
    • IBM Softlayer: input username and API Key, and choose region and Container in the next page.
    • RackSpace: input username and API Key, and choose region and Container in the next page.
    • OpenStack Swift compatible cloud services: input the identity server address and choose the KeyStone protocol version which the server supports:
      • Version 1.0: input username and API Key
      • Version 2.0: input username, password, Tenant ID or Tenant name (optional).
      • Version 3.0: input username, password, Tenant ID or Tenant name (optional), and Domain ID or Domain name (optional).
      • You can choose the region and Container on the next page after passing the identity service
    • S3 Storage: select a server (Amazon S3, Amazon S3 China, or input a server address directly), then input the Access key, Secret key and Bucket name. If users want to enter user-specified S3 service hosts, they should enter something like "s3.amazonaws.com", or "api.suite-stockage-cloud.sfrbusinessteam.fr" in the S3 Server Address field.
    • hicloud S3: input Access key, Secret key, and Bucket name.
    • SFR NAS Backup: input Access key, Secret key, and Bucket name.
    • Microsoft Azure:select a server, input the Blob Storage Access key, and select a Blob container.
    • Backblaze B2: input Account ID, Application key and select a Bucket.
  3. Once authentication has been successful, fill in the following fields and then click Next.
    • Task name: This name will show on the connection list.
    • Local path: Select a local folder. All directories and files within this folder will be synced to the remote folder.
    • Remote path: Select a remote folder. All directories and files within this folder will be synced to the local folder.
    • Sync direction: Select whether you want the sync to be Bidirectional,Download local changes only, or Upload local changes only.
    • Check the box next to Data encryption to enable client-side data encryption.
    • Check the box next to Don't remove files in the destination folder when they are removed in the source folder. if needed.
    • Schedule settings: Go to this section to enable your schedule for file syncing.
  4. To further adjust your sync settings, click Advanced settings.
    • You can prevent certain files from being synced by unchecking any folders you don't want synced, by setting a max file size limit, or filtering out certain file names or file extensions:
      • By folder: uncheck any sub-folders you don't want synced.
      • By maximum file size: If a file is bigger than your specified size, it will not be synced.
      • By file name: Any file with the designated file name will not be synced.
      • File extension: Any designated file extension will not be synced. Add *.[extension] to the table, e.g. *.iso.
  5. Click Apply to save your settings.

Note:

  1. Each user credential can only be used for creating one connection. You can create multiple connections all with different user credentials, but not duplicate connections with the same user credential.
  2. Due to Baidu's limitations, you are only allowed to sync files to the My Application's Data > Cloud Sync folder in your Baidu Cloud storage.
  3. File or folder names that end with a period (.) or a space will be renamed as "file name._DiskStation_modified date_TailCharacterConflict".
  4. When using Cubby via WebDAV, if a folder containing files is deleted, Cubby server will recreate it after syncing. (For example, if you delete 'folder /A', Cubby will download the folder and its contents as 'folder /a'.)
  5. As a general rule, files will not be synced by Cloud Sync under the following circumstances:
    • The folder or file path contains the following characters:
      * : ? \ / " < > |
    • The file name starts with any of the following:
      ._ ~.SYNOPPSDB
    • The file/folder name is or contains any of the following:
      .ds_store desktop.ini @eadir thumbs.db .SynologyWorkingDirectory #recycle Icon\r $Recycle.Bin @sharebin @SynologyCloudSync cloudsync_encrypt.info
    • The folder or file path is longer than 2048 characters.
    • The file name is longer than 255 characters.
    • The folder or file is located in a mount point or an external storage device.
  6. In special cases, files will not be synced by Cloud Sync under the following circumstances:
    • For Google Drive if:
      • The size of a single file exceeds 5 TB.
    • For Baidu Cloud if:
      • The file name starts with a period (.).
      • The file/folder name is, or contains any of the following:
        .baohe .cache
    • For Dropbox if:
      • The file name starts with any of the following:
        .dropbox .cache
      • The file/folder name is, or contains .dropbox.
    • For Box if:
      • The size of a single file exceeds your account limit.
      • The type of the file is bookmark.
    • For OneDrive if:
      • The type of the file is a note document.
      • The size of a single file exceeds 10 GB.
      • The file name begins wth a space.
      • The folder is shared by other people.
    • For OneDrive for Business if:
      • The download size of a single file exceeds 10 GB.
      • The file name is longer than 128 characters.
      • The full file path is longer than 208 characters.
      • The folder or file name contains the following characters:
        \ / : * ? " < > | # { } % ~ &
      • The folder or file name begins with a space or the following characters:
        " ~ " " . "
      • The folder or file name ends with the following characters:
        " . "
      • The folder or file name ends with the following:
        _files _Dateien _fichiers _bestanden _file _archivos _tiedostot _pliki _soubory _elemei _ficheiros _arquivos _dosyalar _fitxers _failid _fails _bylos _fajlovi _fitxategiak _private _t _w
      • The file name contains the following:
        ehthumbs.db .ashx .asmx .json .soap .svc .xamlx
      • The file has the following extensions:
        tmp ds_store ashx asmx json soap svc xamlx htc swf jar aspx master ascx
      • The folder or file name is one of the following:
        forms
      • The folder name contains the following:
        _vti_
    • For hubiC if:
      • The size of a single file exceeds 5 TB.
      • The folder name is or contains .ovhPub.
    • For Google Cloud Storage if:
      • The size of a single file exceeds 5 TB.
      • The folder or file path contains the following characters:
        : * ? " < > | \ / # [ ]
      • The file/folder name is blank.
      • The folder or file path is longer than 1024 characters.
    • For OpenStack Swift compatible cloud services (IBM SoftLayer, RackSpace, RackSpace UK):
      • The folder or file path is longer than 1024 characters.
    • For Amazon Drive if:
      • The size of a single file exceeds 45 GB.
    • Amazon S3 compatible cloud services (Amazon S3, Hicloud S3 and SFR Stockage) if:
      • The folder or file path contains the following characters:
        : * ? " < > | \ / { ^ } % ` ] [ ~ #
    • For Amazon S3 and SFR Storage if:
      • The folder or file path is longer than 1024 characters.
    • For hicloud S3 if:
      • The folder or file path is longer than 255 characters.
      • The size of a single file exceeds 1 TB.
    • For Amazon S3 if:
      • The size of a single file exceeds 5 TB.
    • For SFR if:
      • The size of a single file exceeds 3.9 GB.
    • For Microsoft Azure if:
      • The size of a single file exceeds 195 GB.
      • The folder or file name is .synoemptyblob.
      • The full file path is longer than 1024 characters.
      • The file name is longer than 255 characters.
    • For Backblaze B2 if:
      • The folder or file name is .bzEmpty.
      • The full file path is longer than 1000 characters.
  7. When setting file names you don't want to sync, on Windows if a file name is capitalized and another has the same name in lower case, it will be considered the same file name (ex. A.txt and a.txt) but on Linux and Mac systems they will be considered to be different file names.
  8. Cloud Sync follows the OAuth authentication standard, as does Microsoft OneDrive. OAuth2 requires another server (which is hosted by Synology and located in Taiwan) to complete the authentication. Your Synology NAS will not remember or keep your account password. Your user credentials will only be used for the purposes of file transfer and syncing. Cloud Sync will not access or disclose any other personal account information such as contacts.
  9. Cloud Sync does not impose any single file size limit. You can sync as big a file as the public cloud services allow.
  10. Support for Megadisk allows you to use Synology NAS as backup storage for Megadisk. Please note that, depending on your region and various conditions, the upload speed from Synology NAS to Megadisk might be limited, so we do not encourage using Megadisk as backup storage for your Synology NAS.
  11. Google Cloud Storage Nearline Storage Class is designed for data that is not frequently modified, so when you edit or delete a file, early deletion charges may apply.
  12. When uploading to Google Cloud Storage, Cloud Sync will not enable object versioning.
  13. If a single file exceeds the allocated segment size, OpenStack Swift will upload it using Dynamic Large Objects.
  14. OpenStack Swift Container name cannot exceed 255 characters and cannot include '/'.
  15. Amazon Drive does not support login with Amazon in China and Japan marketplaces. Please see the Platform Limitations provided by Amazon Drive.
  16. Data encryption:
    • To enable data encryption, you must have read-write permission to the remote root folder.
    • Once you have enabled encryption, you cannot disable it or change its password.
    • Local files on your NAS will remain unencrypted.
    • Each public cloud account has only one encryption key.
    • Once encryption has been enabled, Cloud Sync will create a folder named @SynologyCloudSync on the public cloud. Please do not change the files within that folder.
    • An Export button will appear in Settings upon first use. Click the button to export the key, and keep it in a safe place.
  17. Amazon Infrequent Access Storage is designed for data that is not frequently modified, so when you edit or delete a file, early deletion charges may apply.
  18. When configuring a Google Drive sync task to be Download remote changes only, you can also enable Convert Google online documents to Microsoft Office or jpeg formats to keep an offline copy of your Google Docs. Note that the changes made to the offline office documents will not be converted and updated back to Google Docs.
  19. With Enable advanced consistency check ticked, Cloud Sync compares the hash (in addition to file size and last modified time) of each file between the public cloud and the NAS to enhance the integrity check of the sync results. This will require more time and system resources, and depends on the public clouds' support for advanced attributes. Please refer to the bottom of the page for more information.
  20. Backblaze B2 Bucket name must be a minimum of 6 characters long and a maximum of 50 characters long. Names that start with "b2-" cannot be used.
  21. To sync the files in Google Photos to Synology NAS via Cloud Sync, please launch your Google Drive and then go to Google Photos > Settings > General > Create a Google Photos folder > check the box Automatically put your Google Photos into a folder in My Drive > click Done to finish. Afterward, please create a task on Cloud Sync and select the Google Photos folder as the remote path.

Manage Connections

Once a connection has been successfully created, you can view and modify the connection information.

To manage connections:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Under the Overview tab, click Manage to do any of the following:
    • Pause syncing: Pause the syncing operation.
    • Resume syncing: Resume the syncing operation.
    • Unlink: Remove the connection of your Synology NAS and the public cloud service.
    • Edit connection: If authorization of your public cloud account has been revoked or expired, you can click Edit connection to update your information and connect again.

To manage schedule settings:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Schedule > Schedule settings to configure the following:
    • Check the box Enable to enable the schedule for file syncing.
    • Use the scheduling grid to set the schedule for file syncing:
      • Run: File syncing will be performed during the selected period.
      • Suspend: No file will be synced during the selected period.
      • Click Apply to save your settings.

Note:

Backup tasks will be terminated when entering the suspend mode.

To edit a connection settings:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Settings > General settings to configure the following:
    • Connection name: This name will appear on the connection list.
    • Polling period: After Cloud Sync has finished syncing with the public cloud, Cloud Sync will sync again after the set period of time.
  3. Click Apply to save your settings.

Note:

Polling period refers to how often Cloud Sync polls for changes on the public cloud and syncs the changes to the local folder. For example, if you set your polling period as 1 hour, Cloud Sync will connect to the public cloud and search for file changes every hour. The maximum polling period is one day (86400 seconds).

To manage Traffic Control:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Settings > Traffic Control to configure the following:
    • Maximum upload rate
    • Maximum download rate
  3. If the value of this field is 0, it means that there is no limit to the rate of file transfer.
  4. Click Apply to save your settings.

Note:

The traffic control setting applies to the entire public cloud connection, and is shared by all files being transferred concurrently.

To manage S3 advanced settings:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Settings and under Amazon S3 advanced settings, do any of the following:
    • Amazon S3:
      • Enable Amazon S3 reduced redundancy.
    • Amazon S3 and Hicloud S3:
      • Enable server side encryption (AES-256).
    • Amazon S3, Hicloud S3 and SFR Storage:
      • Select upload part file size.
  3. Click Apply to save your settings.

To manage OpenStack Swift advanced settings:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Settings and under OpenStack Swift advanced settings, do any of the following:
    • Select the segment size.
  3. Click Apply to save your settings.

To manage Backblaze B2 advanced settings:

  1. Select the connection you want to edit from the connection list on the left panel.
  2. Go to Settings and under Backblaze B2, do any of the following:
    • Select the upload part file size.
  3. Click Apply to save your settings.

Manage Sync Task List

After successfully connecting with the public cloud services, you can view, add, delete, or edit your sync tasks.

To add a sync task:

  1. Select a connection from the connection list on the left.
  2. Go to the Task list tab.
  3. Click Create and follow the wizard to create a new sync task.

Note:

When selecting a folder to sync, it cannot be in the same directory as one already synced in the same connection.

To remove a sync task:

  1. Select a connection from the connection list on the left.
  2. Go to the Task list tab.
  3. Select a sync task and click Unlink.

Note:

After unlinking a task, a full re-sync might be required if you wish to link again. When you set up a new connection, Cloud Sync will automatically compare existing files and only upload/ download the changes that have been made.

To manage Cloud Sync selective sync settings:

Selective Sync is a feature of the Cloud Sync application that allows you to filter the files or select the folders you want to sync to the public cloud service. Selective Sync allows you to ensure you have only the files you need on the public cloud service or vice versa.

  1. Select a public cloud service from the connection list on the left.
  2. Go to the Task list tab.
  3. Select a sync task and click Edit.
  4. Go to the Folder tab and do the following:
    • Select the folders you want to sync.
    • Click Apply to save your settings.
  5. Go to the File Filter tab and do the following:
    • under Filter By File Size, you can prevent certain files from being synced by setting a maximum file size.
      • Maximum file size should be between 1~10240 MB, with 0 meaning unlimited.
    • Under Filter By File Type, you can prevent certain files from being synced by entering the file name or unchecking the files or file extensions that you do not want to be synced.
      • File name: Any file with the designated file name will not be synced to the public cloud service. The maximum length of the file name is 255 characters.
      • File extension: Any designated file extensions will not be synced to the public cloud service. Add *.extension to the table, e.g. *.iso. The maximum length of the file extension is 255 characters.
  6. Click Apply to save your settings.

To modify sync direction:

  1. Select a public cloud service from the connection list on the left.
  2. Go to the Task list tab.
  3. Select a sync task and click Task settings.
  4. In the Settings tab, configure any of the following:
    • Sync direction: Select whether you want the sync to be Bidirectional,Download local changes only, or Upload local changes only.
    • Check the box next to Don't remove files in the destination folder when they are removed in the source folder.if needed.

Note:

Cloud Sync will sync all newly added files and folders by default.

Manage Cloud Sync from DSM System Tray

After you have installed and launched Cloud Sync, a package icon will appear at the top-right corner of your DSM system tray. You can easily and efficiently manage Cloud Sync and perform the following actions from the system tray:

  • Monitor recently modified files.
  • View the transfer speed and progress for current transfers.
  • Pause or resume your connections.
  • Open the paired sync folders.
  • Launch Cloud Sync.

Settings

Administrators can click the Settings icon on the bottom right and under Administrator Controls, specify Cloud Sync database location, maximum concurrent uploads/downloads, maximum number of logs kept, and switch to administrator mode.

To specify the database location:

  1. Select a volume in the Database Location Settings dropdown menu.
  2. Click OK to save your settings.

To specify the concurrent uploads/downloads:

  1. Select a number in the Concurrent uploads/downloads dropdown menu.
  2. Click OK to save your settings.

To specify maximum records in history log:

  1. In the Maximum records field, input a number between 5 and 100000.
  2. Click OK to save your settings.

To enable administrator mode

  1. Select Enabled in the Admin mode drop-down menu to manage the connections of all Cloud Sync users. You can specify the order of these connections by user account or cloud type in the overview.
  2. Click OK to save your settings.

For Advanced Users

To ensure your files and folders sync correctly, please note the following information.

Supported attributes of the public clouds

Platform File hash Last modified time
Dropbox X O
Google Drive O (md5) O
Baidu O (md5) X
Box O (sha1) O
hubiC O (md5) O (1)
Amazon S3 O (md5) X
WebDAV X X
Yandex X X
Amazon Drive O (md5) X
MegaFon O (md5) O
OpenStack Swift O (md5) O (1)
Google Cloud Storage O (md5) O (1)
Microsoft OneDrive O (sha1) O
Microsoft OneDrive for Business X X
Microsoft Azure O (md5) O (1)
Backblaze B2 O (sha1) O (1)

1: These public cloud providers do not allow the last modified time attribute to be updated, but provides a custom file attribute field for third-party apps like Cloud Sync. Cloud Sync will save the last modified time in the customized file attribute field. This means Cloud Sync's last modified time will not be updated on the public cloud web interface and other sync clients.

Note:

  1. Only Dropbox and Google Drive allow last modified time to be updated by third parties. This means the last modified time of other public cloud services is always the upload time of the file.
  2. Hash values are not available for files uploaded to Amazon S3 via multi-part upload.
  3. Hash values are not available for files uploaded to OpenStack Swift via Dynamic Large Object upload.
  4. Hash values are not available for files uploaded to Backblaze B2 via b2_upload_part upload.
  5. Cloud Sync uses Google Cloud Storage's md5 hash. The crc32 hash of composite object is not adopted.

Metadata that will not be synced to your public cloud services:

  • UNIX read/write and execution permissions.
  • Windows ACL.
  • Mac's extended attributes.
  • Last modified time of the folders.
  • Last modified time of the files (for Baidu Cloud, Microsoft OneDrive for Business, Amazon S3, Amazon Drive, WebDAV, Yandex).

Default action for conflicted copy:

If a file or directory is modified on both your local Synology NAS and remote public cloud account at the same time, Cloud Sync will try to keep the local changes as much as possible, and the remote changes will be saved as one revision if the cloud service supports versioning.

The following cloud services prevent your Synology NAS from entering System Hibernation:

  • hubiC
  • Amazon S3 compatible cloud services (Amazon S3, hicloud S3 and SFR NAS Backup)
  • WebDAV
  • Megafon Megadisk
  • Google Cloud Storage
  • OpenStack Swift compatible cloud services (IBM SoftLayer, RackSpace, RackSpace UK)
  • Microsoft Azure
  • Backblaze B2

For more details about services that may affect system hibernation, please see this FAQ

Why does Cloud Sync continuously download the same file from Baidu Cloud?

After files have been uploaded to Baidu Cloud, Cloud Sync will compare the file hash on both sides to confirm consistency. We found that in many cases, Baidu will respond with an incorrect hash value, causing Cloud Sync to detect that the files on the public cloud differ from those on your Synology NAS. Because of this, Cloud Sync will try to align the versions, and commence sync again, causing the repeated download of the same file.

Why is Cloud Sync slower than other cloud services' PC applications?

Due to the below limitations, Cloud Sync might take longer to sync files with public cloud services than the official PC applications such as Dropbox and Baidu.

  • Speed limits imposed by cloud service providers: Although no public cloud service provider has disclosed any information related to this topic, it is highly possible that public cloud servers communicate with their official PC applications through a dedicated tunnel/protocol, or impose bandwidth limitations on third-party applications that access their services on a regular basis (such as Cloud Sync).
  • No incremental update: Some cloud service providers do not releases a public API for developers to track file changes. This means Cloud Sync must re-download and sync the entire file every time a file has been modified, even when you've only made partial modifications. On the other hand, cloud service providers' official PC applications might be able to re-download and sync the modified bits only, reducing sync time.
  • No local network sync: Certain public cloud service providers offer LAN sync, a technique that allows one client to obtain files from existing clients in the same local area network (LAN), thus significantly boosting sync speed. However, LAN sync accesses files in client computers without notifying them, which could possibly become a security backdoor. Therefore, this feature is not included in Cloud Sync.

Given the above limitations, the syncing performance of Cloud Sync shall continue to be enhanced, while also maintaining the safety and security of your Synology NAS.