Ssh – Mount a filesystem using sshfs using the Dropbear server on Yocto firmware

dropbearlinuxsshsshfs

I built a firmware for an embedded board using Yocto. ssh server Dropbear seems to be up and running and working properly. I can login with the root user without a password. Nevertheless, I cannot mount the filesystem from an Ubuntu desktop using sshfs. On the desktop I'm getting:

sudo sshfs -o allow_other root@10.42.0.68:/ /mountpoint
remote host has disconnected

in Poky instead I can see in /var/log/messages:

May  7 00:25:37 raspberrypi3 authpriv.info dropbear[537]: Child connection from 10.42.0.1:48010
May  7 00:25:38 raspberrypi3 authpriv.notice dropbear[537]: Auth succeeded with blank password for 'root' from 10.42.0.1:48010
May  7 00:25:38 raspberrypi3 authpriv.info dropbear[537]: Exit (root): Disconnect received

Is it possible to increase the verbosity somehow? I tried to add "verbose = 1" in /etc/default/dropbear but this is probably wrong as the server does not even start anymore. Maybe sshfs is not supported at all by dropbear?

Best Answer

As for you trying to do SSHFS with Dropbear: the question is that SSHFS needs SFTP, while Dropbear only supports SCP.

So there is not much a point in debugging why it is happening.

From the dd-wrt wiki: https://www.dd-wrt.com/wiki/index.php/Sshfs

Since Dropbear (the default ssh server) apparently does not support sshfs, you will need to install and run Openssh instead.

So indeed, SSHFS is not supported by Dropbear as you suspected.

P.S. For the benefit of other readers, Dropbear is a lightweight replacement for OpenSSH used widely in embedded systems/routers/ iOTs.

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