Uppsala Multidisciplinary Center for Advanced Computational Science

My connection to UPPMAX is dropped / timed out

If you need a long running interactive session to the cluster it might time out after a while if there's no activity over the connection. This is usually due to different network equipment and configurations along the way between your computer and our systems.

A workaround to remedy this is to change your SSH clients "keep alive" settings. On Mac/Linux you can try this by adding the ServerAliveInterval option when connecting:

ssh -AX -o ServerAliveInterval=10 user@milou.uppmax.uu.se

The number 10 tells SSH how many seconds to wait until it will send a keep alive message to the SSH server on Uppmax end. This number might have to be adjusted for each specific occasion, as it depends on what ISP and network the user is using when connecting. But if it appears to help, then a line "ServerAliveInterval 10" can be inserted into the file ~/.ssh/config on the client, that way you don't have to append the option manually each time you're connecting.

If you use PuTTY or MobaXTerm on e.g. Windows, then there should be similar settings available in the menus.