Installation and first impressions
How easy is it to install and use each option for the first time?
Using your distribution’s (distro) package manager to install software wherever possible just makes sense, but several of the choices in our Roundup come as distroagnostic packages. The easiest to install are Rsync, BitTorrentSync and Syncthing – the former because most distros have it installed by default, while the other two each come as a tarball containing the executable program, ready to run from wherever you unpack it, and Syncthing also provides Debian/ Ubuntu packages.
Unison is provided as source code for a traditional Linux install method or you can use your package manager. OwnCloud itself is easy to install as a tarball that you unpack in a directory available to your web server, but that’s the catch: it needs a web server, with Apache being the popular choice. While the others all communicate directly between computers, OwnCloud needs that server and then you simply install the client on everything else, although you can also use a browser to view the files. This makes the initial setup more of a chore, albeit a well-documented chore, but you only have to do it once. The OwnCloud desktop client defaults to syncing the entire server with an OwnCloud directory on your hard drive. You can also sync individual directories, but you must first remove the default.
BitTorrentSync and Syncthing both use a web interface with their own builtin web server. When you run the program in a terminal it will tell you the port to connect to on localhost. Then it’s simply a matter of following the prompts to sync folders. Naturally, you have to do this on at least two devices. OwnCloud is also set up through a web browser, while Unison and the Rsync tool use SSH as the underlying protocol. If you have already set up SSH – preferably using key authentication rather than passwords – between the devices they should just work once you tell them what to sync.
The default for Unison is the home directory on each computer but this is configurable by creating profile files. Unison is the only one of the programs with a traditional desktop interface. From here you can choose and set up synchronisation profiles (these enable you to sync with different devices or different sets of files), trigger synchronisation manually, handle conflicts and read the manual.