For my work, I need to keep multiple ssh and sshfs tunnels open. After an upgrade to Ubuntu 16.04, my ssh tunnels started to hang after some period of inactivity. Now if a ssh tunnel hangs, all one has to do is close the terminal. So inconvenient but managable. But if a sshfs tunnel hangs, then a simple ls command can hang the terminal. Or if you are using Nautilus (file manager), simply trying to browse to the mounted folder will cause a hang making you force quit the application. Lastly, desperation kicks in and you now try to force a umount, but OS will complain saying some resource is busy. To summarize, I am forced to restart every time a sshfs tunnel hangs which is really annoying.
To resolve this issue for ssh, we use the option ServerAliveInterval. Quoting from the man page of ssh_config, > ServerAliveInterval
> Sets a timeout interval in seconds after which if no data has been received from the server, ssh(1) will send a message through the encrypted channel to request a response from the server. The default is 0, indicating that these messages will not be sent to the server, or 300 if the BatchMode option is set. ProtocolKeepAlives and SetupTimeOut are Debian-specific compati- bility aliases for this option.
Therefore, either modify your ssh_config file or use the following command
ssh -o ServerAliveInterval=300 user@machine-nameSo far, 300 = 5 minutes has served me well. Experiment with the value to find one that works for you.
For sshfs, use the following command
sshfs user@machine-name -o ServerAliveInterval=300 mount-path