Folder preferences allow you to configure synchronization on a folder-by-folder basis specifying how Sync will search for peers as well as how it will treat files in certain situations
Note: available on desktop platforms only.
To open Folder Preferences, hover your mouse over the folder, click the dots and then choose ‘Preferences’.
In the Preferences window you'll see a list of configuration options for the selected folder:
The title bar of the Preferences window contains the icon indicating permission type as well as folder name and a full path to the folder directory . Below the title bar, you can see the list of available options.
LOCAL FILES
Store deleted files in folder archive
If some peer with a Read & Write Key changes or deletes a file, it will be changed or deleted on the other peers' devices, too. However, before changing or deleting a file they will be copied to ".sync/Archive" subfolder. By default, these archived files will stay in the Archive for 30 days, just in case you need them, before being automatically cleaned up and removed by Sync. If you disable this option, files deleted by Sync (due to action on another peer) will no longer be copied to Archive.
Also, with Archive disabled, files that you rename or copy on a remote peer will be re-downloaded instead of just renaming or copying the local file (read more)
Overwrite any changed files (for Read-Only folders)
For a Read Only shares, this option causes Sync to overwrite any changes you have made in the folder, including files you have added. You should be careful with this option, since it is potentially destructive to your data.
This option is disabled for Read-only folders with Selective Sync ON.
Use relay server when required
By default, Sync does its best to establish direct connection between peers to achieve maximum speed. However, if direct connection is not possible for whatever reason (sophisticated NATs, firewalls, proxy servers, etc.) this option will allow Sync to establish a connection via Resilio's relay server and transfer data without a direct connection. Note that it can impair the syncing speed.
Use tracker server
Tracker server helps peers to find out each other's IPs to use them for direct connection. If you disable tracker server, make sure that your peers can "see" each other in LAN by setting "Search LAN" preference or by defining "Predefined hosts".
Search LAN
Allows Sync to search your local network for other instances of Sync having the same Keys as yours. The fastest way to discover other peers in LAN. If you choose to disable this option, either make sure that the use of Tracker server is allowed or configure predefined hosts.
Use predefined hosts
A list of IP:port pairs Sync connects to. Can be very useful in high-security networks where LAN search over multicast and contacting Tracker server is impossible or prohibited. Use this option on all peers!
Address - is the IP address or DNS name of remote peer. Make sure that DNS name resolves into correct IP, especially if there are a few DNS servers in the network. Use public or local IP address for peers located in different networks or LAN accordingly.
Port - Sync's listening port of that remote peer, as defined in Sync preferences there.
You can define several hosts so that your local Sync instance connects to them all directly.
To get the Predefined hosts dialog, select the ‘Use predefined hosts’ checkbox.
File download priority
Defines the priority of downloaded files. Files can be prioritized by size or by modification time. Read more about it here.