Postmodern Sysadmin

A blog about servers and junk

Dropbear With Mosh on a Low End Server

I love my low end boxes. I also love mosh.

Low end boxes usually are tight on resources, so Dropbear is often used as a lightweight ssh server. Mosh is mostly tested with openssh-client/server, so I think there are some bugs.

But it can work, just make sure:

  1. You are using the same version of mosh on the server as you are on your client. (otherwise they may not support the same command line options)

  2. Make sure you have have a en_US.UTF-8. Mosh requires UTF8, and low end boxes usually have a bare install without this local. Run:

locale-gen --no-archive en_US.UTF-8

For a reproducible puppet snipped:

package { 'mosh': ensure => latest }
ensure_packages(['locales'])
exec { "/usr/sbin/locale-gen --no-archive en_US.UTF-8":
 creates => '/usr/lib/locale/en_US.utf8',
}
  1. Run mosh more than once. There is some sort of race condition or bug which prevents mosh from grabbing a tty. Running it multiple times will get it to work eventually. I haven’t tracked down the root cause.