Hi all,

I have a small script that copies some files from a local machine to a remote every ten minutes or so. Most of the time it works fine, but once in a while scp looses connection and stops and the script hangs. I am running ssh-agent in bash-mode.

What I do is something like this:

while true; do
scp file user@server: path
sleep 600
done

and I just want scp to close down if there is an error, so that the script can continue.

Any help will be much appreciated!

probably
scp .... || true
will help

but you may try to use crontab instead of while loop

1 members found this post helpful.

It certainly looks like crontab is what I want to use. I'll give it a try, thanks!

Do you want the script to try to copy again immediately if scp loses the connection?

Either way, if the script is copying the same file over and over again, you may want to try rsync instead. The utility rsync runs over SSH but transfers only the changes. So if you are resuming transfer of a file after the connection is lost, it will pick up where you left off. scp cannot do that.

1 members found this post helpful.

I is indeed the same files that I transfer, but it is not important that the file transfer is resumed - it is ok to wait for the next transfer after 10 minutes.

I am not sure whether it is scp or ssh-agent that cuts the connection once in a while. If it is ssh-agent, I guess using rsync will not solve the problem. But I will try rsync also and see it there is a difference.

For now, It looks like also works. If scp prompts for a password and stops, the connection is cloes after 30 seconds and the script can resume. The -B option stops password prompt. I have not tested yet if it is -B or -o that solves the problem.

The agent is only used in establishing the initial connection. Specifically it is involved in the authentication. So the disconnection is happening for some other reason, unless the initial connection is not actually happening in the time alloted. You can throw a -v in there temporarily to increase the amount of information it shows you.

Since you are copying the same file again and again, it looks like rsync is the way to go. It actually runs over SSH these days so it can use keys and the agent. If you need to specify some weird options or specific keys then that can be passed to rsync

You can also make the configuration options permanent by putting them in a ~/.ssh/config entry for the target host.

if it was the same file, I would try rsync instead of scp (too late)