Hi,

I have 2 hosts that I can connect them through SSH. In one host, after a while, I get the error `Write Failed: broken pipe.` In the other host, I don't get this error.

I don't understand why in one host, I get this problem, and in another host everything is ok.

So, I have set a SSH connection with tmux, and inside the remote host I run a foreground process (celeryd). But, even when the SSH session fails, and I reconnect to the dropped session, the foreground process has died.

I would like that the foreground process won't come down when the SSH connection is broken. So, I just have 2 solutions:

1. know how to avoid SSH broken pipes, or
2. know how to avoid that the process will die when the SSH connection goes down.


Can anyone can help me on this?

You can't keep a process running in the foreground if the connection fails, because when the connection fails all of your stdin/stdout/stderr pipes break and the process can no longer function. Keeping the connection from failing is all well and good, but sometimes there's nothing you can do if this is a remote system.

The best option is to run it in the background with nohup if you don't need stdin, or in something like screen if you do.

Have you tried using an entry in /etc/inittab to restart the service like:

ssh:2345:respawn:/usr/sbin/sshd -D -p 22

To restart the service if it stops?

SSH broken pipe usually result from connectivity issue. It could be because of network issue or because of misconfiguration in sshd_config. If your sshd was working fine on this server before and it suddenly started happening (assuming you have not made any changes to /etc/ssh/sshd_config) then it is most probably a network issue. It will be good if you run a ping test from another machine continuously to test that or check with your network team.

Yes, if you are running any foreground process and if your ssh session gets killed or terminated the foreground process will get killed as well.

To avoid ssh broken pipes please see the above information I have provided. To avoid process getting killed it will be a good idea to run it in background. You can run it with nohup and & eg:

Here I am running dd with nohup and & to push it to background instead of foreground. So even if I exit from shell it will be running in background.