System information - performance statistics exception on RPi3

Hi All,
I have a RPi3 with OMV 3.0.50.
The performance statistics not works (it never worked, since i installed the OMV 3.x).
A sample line from the system log:

Oct 31 07:45:01 my rrdcached[1287]: queue_thread_main: rrd_update_r (/var/lib/rrdcached/db/localhost/cpu-0/cpu-idle.rrd) failed with status -1. ('/var/lib/rrdcached/db/localhost/cpu-0/cpu-idle.rrd' is not an RRD file)

...and throw exeption, when i click on the refresh button:

exception 'OMV\ExecException' with message 'Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C; omv-mkgraph 2>&1' with exit code '1': ERROR: '/var/lib/rrdcached/db//localhost/cpu-0/cpu-idle.rrd' is not an RRD file' in /usr/share/php/openmediavault/system/process.inc:175
Stack trace:
#0 /usr/share/openmediavault/engined/rpc/rrd.inc(54): OMV\System\Process->execute(Array)
#1 /usr/share/php/openmediavault/rpc/serviceabstract.inc(528): OMVRpcServiceRrd->{closure}('/tmp/bgstatusgt...', '/tmp/bgoutput1Z...')
#2 /usr/share/openmediavault/engined/rpc/rrd.inc(56): OMV\Rpc\ServiceAbstract->execBgProc(Object(Closure))
#3 [internal function]: OMVRpcServiceRrd->generate(NULL, Array)
#4 /usr/share/php/openmediavault/rpc/serviceabstract.inc(124): call_user_func_array(Array, Array)
#5 /usr/share/php/openmediavault/rpc/rpc.inc(84): OMV\Rpc\ServiceAbstract->callMethod('generate', NULL, Array)
#6 /usr/sbin/omv-engined(516): OMV\Rpc\Rpc::call('Rrd', 'generate', NULL, Array, 1)
#7 {main}

How do I correct this?
This is a bug (needs some system level changes)?
Thanks for the kind advice.

Zsolt

No, I didn't upgrade fro 2.x. I installed 3.0.41 image first.
Statistics didn't work.
Nor, after update to 3.0.50.

I do not use anything important to justify the statistics, I was just curious only.

I want to build a home cloud server, with some web serving (nginx plugin),
media server (minidlna or plex), ftp (with SSL/TLS only), webdav (SSL/TLS only), some SMB/CIFS for my Windows PC-s,
and I want to try Owncloud, how it works.
I think OMV is the best basis to try these.
Performance stats is only some info for me about RPi3 performance.

I didn't try omv-firstaid.
Do you think it correct the p. statistics?

I solved!

The omv-firstaid > rrd check fails, and it has not solved the problem.

But i found the mistake:
I found this: all RRD file is malformed in all subdirectories of the directory /var/lib/rrdcached/db/localhost/.
The original error message was true: '/var/lib/rrdcached/db/localhost/cpu-0/cpu-idle.rrd' is not an RRD file.
Every RRD file header must start with "RRD.0003", but doesn't in the files above.
(And all files are wrongly dated: 7th day of december in this year. Future?)

I stopped the monitoring, then i deleted all RRD files in the subdirectories above.
All performance statistic works, after restart the monitoring.
RRD files recreated in the correct format.

I don't know, but I think maybe the original RRD files are corrupt in the OMV install disk image for RPi.
However, you are right, because the monitoring is sufficiently slows down the RPI.