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Thumbnails and media files previews

Feature availability

Available from: 4.2.0
Available for:

  • Windows - Access to files on a Caching Gateway over SMB, using File Explorer.
  • MacOS - Access to files on a Caching Gateway over SMB and local folders with TSS (transparent selective sync) enabled.
  • Linux - Access to files on a Caching Gateway over SMB.

With the placeholder preview thumbnails feature, your file manager can present thumbnail previews for placeholder files. This lets you quickly get an idea of the contents of a media file without having to wait for it to be fully downloaded.

When generating file previews, a portion of a file is retrieved. The exact behavior isn't fixed - it generally depends on the file size and format. For smaller files (like images), the entire file is usually downloaded. For larger media files, different approaches may be used: in some cases, the whole file is downloaded, while in others only certain segments or metadata are retrieved to enable progressive loading or quick previews.

Enable placeholder preview thumbnails

Windows

To enable placeholder preview thumbnails for SMB shares on Microsoft Windows workstations:

  1. Ensure that the placeholders_as_regular_files_for_smb_server custom parameter in your job profile does not have value other that 1 (which is its default value).

  2. In File Explorer open folder options and make sure the Always show icons, never thumbnails option is disabled.

    Preview Thumbnails View Settings

Thumbnail previews may not be supported in certain file managers like Total Commander. In such cases, the system may need to fully hydrate the file to generate a thumbnail. This can lead to a delay in thumbnail display and might require refreshing the contents of the folder.

MacOS

Thumbnail previews for placeholder files accessed over SMB is enabled by default.

Thumbnail previews for local placeholder files with the TSS are enabled by default. To disable previews, in Agent Profile add the fs_fuse_download_block_list custom parameter with value: 

Finder.app;QuickLook;com.apple.appkit.xpc.openAndSavePanelService;/usr/libexec/lsd;com.apple.iTunesLibraryService;/System/Library/CoreServices/iconservicesagent;/System/Applications/Music.app/Contents/MacOS/Music;/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent;/Applications/CleanMyMac X.app;/Applications/Resilio Connect Agent.app/Contents/MacOS/Resilio Connect Agent;/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mds;/System/Library/ExtensionKit/Extensions/ImageThumbnailExtension.appex/Contents/MacOS/ImageThumbnailExtension;/System/Library/ExtensionKit/Extensions/AudiovisualThumbnailExtension.appex/Contents/MacOS/AudiovisualThumbnailExtension;/System/Library/ExtensionKit/Extensions/OfficeThumbnailExtension.appex/Contents/MacOS/OfficeThumbnailExtension

To optimize local storage usage, enable Progressive Hydration by adding the tss_hydration_policy: 0/1 parameter to the job policy. For details, see File streaming: progressive Hydration in TSS.

Linux

To set up thumbnail previews for placeholder files accessed over SMB, in file manager's preferences, in the Performance section, select the option to show thumbnails for all files.

Preview Thumbnails Linux