There are two ways to control BOINC on Linux:

• boincmgr: a GUI; also known as the BOINC Manager
• boinccmd: a command-line tool

Each of these requires a 'key' to communicate with the BOINC client. The client creates this key and stores it in a file gui_rpc_auth.cfg in the BOINC data directory.

'Not found' errors

To locate the key file, boincmgr and boinccmd do the following:

1. boincmgr looks in a directory specified with the --datadir command-line option (boinccmd doesn't have this option).
2. They look in the current directory.
3. They check for a configuration file /etc/boinc-client/config.properties and look for a line of the form

   data_dir=PATH
   

   This tells them where the data directory is. If you install BOINC using a package manager, this is set up automatically.
4. They look in /var/lib/boinc.

If none of these locates gui_rpc_auth.cfg you get a 'not found' error message. To fix this, either reinstall BOINC, or create a configuration file as above, or run the program in the BOINC data directory, or use the --datadir option in the Manager.

'Can't be read' errors

If you get an error message like gui_rpc_auth.cfg exists but can't be read, the problem is file permissions. You can generally fix this by adding yourself to the 'boinc' group:

sudo usermod -a -G boinc $USER
exec su $USER