# Smart Synchronization

The smart sync feature allows making files available offline. You can also choose to make explicitly all or only selected files and folders available for offline use. Changes to files are saved in a local cache first and uploaded in the background as soon as a connection is available.

## Bookmark Options

You can change the synchronization options for a bookmark in Connect Mode.

• Default: Use setting from Preferences

• Online: Do not synchronize any files to your computer. You can only access this volume when a connection is possible to the server or cloud storage. Files are accessed on demand from the remote when opened and do not take up any local disk space.

• Smart Synchronization: Files opened are made available for later offline access. You can explicitly make files available offline using the context menu.

## Status of Files

Files and folders on a mounted volume have a status icon overlay in File Explorer (Windows) and Finder (macOS).

Note

Please make sure to enable the Mountain Duck Integration in System Preferences → Extensions → Finder on macOS.

### Up to Date

The file or the contents of a directory has been opened and downloaded to your computer and therefore currently synced with the server or cloud storage. The file takes disk space on your computer and can always be opened even when no connection to the server or cloud storage is possible. New files in a directory on the remote server will appear as Online Only and are not downloaded automatically. Files copied to a volume are kept cached by default.

### In Sync

The file or directory is selected to be synced with the server or cloud storage to always keep offline. The file takes disk space on your computer and can always be opened even when no connection to the server or cloud storage is possible. New files in a directory on the remote server will be downloaded automatically.

### Online Only

The file can only be opened when a connection to the server or cloud storage can be made. The file does not take any space on your computer. The file is downloaded on demand when you open it.

### Sync in Progress

The file or directory is currently syncing with the server or cloud storage.

### Sync Error

There was an error updating the file after changes. You are missing permission to write to the file or another problem occured. Please contact your web hosting service provider for assistance. To resolve the error, move the file to your local disk, and reload the directory or use the Retry option within the context menu.

### Ignored

The file is only saved in a local temporary location and never synced to the server or cloud storage.

macOS only

Please make sure to enable the Mountain Duck Integration in System Preferences → Extensions → Finder Extensions.

### Keep Offline

Choose Mountain Duck → Keep Offline on Local Disk to make files and folders available offline. The status of the file will change to In Sync. The action is recursive for all contained files when a folder is selected and applies to new files found on the remote storage.

Note

As long as the volume is mounted, files marked Up to Date or In Sync with a green checkmark remain accessible even if the network connection drops. Changes are synchronized in the background when the server is reachable again. This is made possible by caching file contents in an obfuscated cache on a local disk, which is unavailable for direct use.

To reach the context menu right-click on a file or folder in File Explorer (Windows) or Finder (macOS). Refer to Finder Extension & Windows File Explorer Extension.

### Delete on Local Disk

Choose Mountain Duck → Delete on Local Disk to delete the offline copy. The status of the file will change to Online Only. The action is recursive for all contained files when a folder is selected and allows you to quickly free up space used in the cache on your local disk

Note

Files will get cached again regardless this setting if accessed again later (e.g. Finder and Windows Explorer thumbnail preview and media file metadata retrieval).

## Sync Conflicts

A conflict may be caused by two or more users editing the same files at the same time or while on the road before the files are synced. We do not merge changes to files like version control systems do. The file with conflicting edits will be renamed with the current time added to the filename. You will have to compare the changes manually and delete the duplicate file afterwards.

Action

Error Cause

Error State (Overlay Icon)

Remarks

Manual Conflict Resolution

Indexing folder

Missing permission

Sync Error for files with
pending write

Other files are removed from
local cache

Retry

Open placeholder (1) file

file on server

-

Status remains Online

-

Select to keep file offline
placeholder (1) file

file on server

Sync Error

-

Retry

Indexing folder containing
files in write error state

File with write sync error

Sync Error

For error states caused by other Operations
than write, the file is removed on local disk

Retry

Open placeholder (1) file

Directory index is out of sync.

-

File is deleted in local cache

-

Edit file deleted on server

Directory index is out of sync.

-

File is uploaded anew to server

-

Edit file renamed on server

Directory index is out of sync.

-

File is uploaded anew to server

-

on server

Last seen checksum differs from current
checksum on server. (Or timestamp
when server does not offer checksum
verification)

-

Existing file on server is renamed
to <filename> timestamp.<extension>.
Eventually with user preference to

User has to manually merge
the conflicting edits.

Edit file with parent folder
missing on server

Sync Error

-

Move file to different folder
or Retry option in context menu

Move or rename file to target

Directory index is out of sync

-

Existing file on server is renamed
to <filename> timestamp.<extension>.
Eventually with user preference to

User has to manually merge
the conflicting edits.

Move or rename directory to target

Directory index is out of sync

-

Existing directory on server is renamed
to <folder> timestamp.<extension>

User has to manually merge the
conflicting edits.

Move or rename directory that no
longer exists on server

Directory index is out of sync

Sync Error

Directory is removed from local cache

-

Create file that exists already on server

Directory index is out of sync

-

Failure creating file is ignored

-

Create folder that exists already on
server

Directory index is out of sync

-

Failure creating folder is ignored

-

Deleting file already changed on server

Directory index is out of sync

-

File is deleted on server

-

## Sync Progress

Changes to files are uploaded in the background as soon as a connection is available. Progress is reported by animating the status bar icon and a menu item titled Sync in Progress.

Detailed status for current transfers is available in the Sync submenu. Refer to Sync Progress.

### Pause Sync

You can manually pause background syncing by selecting Pause Sync in the submenu for the sync status. Syncing is also paused automatically when your network connection to the server is interrupted but resumed automatically when a connection is restored.

The paused sync status is indicated with a greyed-out icon in the tray (Windows) or status bar (macOS).

## Sync Errors

Files that failed to sync get a sync error badge. You can try to repeat the failed transfer by selecting Mountain Duck → Retry in the context menu.

### Resolve Errors

If a sync error cannot be solved using Mountain Duck → Retry because the server does not allow the operatio due to a permission issue you can resolve the error state on the file or folder by

• Move the file or folder to another location on the volume

• Delete the file or folder

## File History

You can lookup the latest changes to files. Refer to Recent Files