Rrd4j error: too many open files

Hi,
i have openhab running since 2 years now and i have a lot of items persisted with mapdb, rrd4j and 4dbo.

Now i added some more items and now i get errors when i start openhab: too many open files

The error has to do with rrd4j.

Is there a limit for rrd4j? Or where else could be the error?

Also i changed the rrd4j persistence today a little bit. Before there was on some groups only “every minute”. Now i added “every change”. Could that also be the error?

This might be an OS issue.

It seems that some of my *.rrd files were broken. I got errors …could not write *.rrd … and so on.

I removed the files and restartet openhab. Then i got new files and the error was gone…