How to correlate a run with the runner

I have a setup where docker containers run gitlab runners, which connects to my gitlab instance. At the moment we have a problem (error: could not lock config file .git/config: No space left on device), which happens some of the time. The fact that it does not happen all the time, implies there is something wrong with a specific runner. But how can I know which runner has executed a run?

In the logging it says something like Running on c8eda3bbebb9..., but I cannot correlate that hash to any of the runners in my runner overview.

Any idea what that hash means and how to connect it to a specific runner instance?