I also experienced the problem described above on an upgraded 2.0.0p24 (CEE).
I did try
Afterwards I still have a folder per monitored host in my “~/var/pnp4nagios/perfdata/” folder and ~/var/check_mk/rrd/ is empty.
I noticed that e.g. for Filesystem_*.rrd I get the error only for these 2 (but on many hosts):
- Filesystem___growth.rrd
- Filesystem___trend.rrd
Filesystem_*.xml ( mentioned by @andreas-doehler ) files are present for the hosts mentioned in the log and also 4 more rrds per filesystem-service, checkmk does not complain about being present:
- Filesystem___fs_size.rrd
- Filesystem___fs_used_percent.rrd
- Filesystem___fs_used.rrd
- Filesystem___inodes_used.rrd