Can we cleanup data sub directory

Hi

you can delete unused ones, the question is how to do it safe to do not delete production volumes.
It is about data/<storage>/VOLUME/*rrd file.
You can use something like that but leave there some days to do not delete everything in case it stops updating even prod volumes:

find data/<storage>/VOLUME/ -name \*rrd -mtime +10 -exec rm -f {} \;

you can further check in data/<storage>/VOLUME/volumes.cfg if removed file exist there. if so then do not remove it as it is actually configured.

Generall problem is that in this way you might delete even normal volumes which has been removed what might affect historical graphs.

The only workaround would be ignoring snapshot volumes at all, but it is allso wrong when there is any traffic on them which sould be included in volume graphs.