syncthing/relnotes/v2.0.md

Major changes in 2.0

• Database backend switched from LevelDB to SQLite. There is a migration on first launch which can be lengthy for larger setups. The new database is easier to understand and maintain and, hopefully, less buggy.

• Deleted items are no longer kept forever in the database, instead they are forgotten after six months. If your use case require deletes to take effect after more than a six month delay, set the --db-delete-retention-interval command line option or corresponding environment variable to zero, or a longer time interval of your choosing.

• Modernised command line options parsing. Old single-dash long options are no longer supported, e.g. -home must be given as --home. Some options have been renamed, others have become subcommands. All serve options are now also accepted as environment variables. See syncthing --help and syncthing serve --help for details.

• Rolling hash detection of shifted data is no longer supported as this effectively never helped. Instead, scanning and syncing is faster and more efficient without it.

• A "default folder" is no longer created on first startup.

• Multiple connections are now used by default between v2 devices. The new default value is to use three connections: one for index metadata and two for data exchange.