CheckMK Server Influx database - Running out of disk space

Dear CheckMK community,

We have been running checkMK server for a few years now. It’s configured as distributed monitoring system. Recently I saw the folder /var/lib/influxdb/data/grafana has taken most of disk space.

I understand the database includes graphs, logs, configs and such.

What is the best way to purge old data? We would like 1 year worth of historical data and the rest can be deleted. I couldn’t find any options or features in the GUI.

Also a user influxdb owns rights to the folder so I can’t access it even with root privileges which means I can’t really see what’s inside unfortunately.

Is there a safe and easy way to tackle this?

Best regards,