RRDTool Says: "ERROR: opening [...]" and myster

[mszarek]

Hi all,

Sorry if I take up a thread which has been taken yet, but I simply couldn't find such one.

And here follows the description of my problem:
I wanted to graph Errors/Discards history on my switch: I added the graph but Cacti doesn't draw it.
Graph debug mode says:
-- cut --
RRDTool Command:
/usr/bin/rrdtool graph - \
[...]
RRDTool Says:
ERROR: opening '/var/www/html/cacti/rra/switch_mdf_sw01_errors_in_361.rrd': No such file or directory
-- cut --

What could be the reason of such an error? Access rights on rra/ directory look good, especially that many, many graphs work without any problem.

I don't understand why the RRD file is not created.

Maybe following issue is the reason of my problem:
when I create Errors/Discards graph, I'm prompted for specyfying three custom data fields:
- index_type
- index_value
- output_type
I leave them blank because I have no idea what data should be provided.
But what are those fields? What data they request for? Those Custom Data fields are included in "Get SNMP Data (Indexed)" data input method.


I shall appreciate all your help, many thanks in advance!

Greetings

[gandalf]

Did you create the Graphs from Devices page using Create Graphs for this Host?
Reinhard

[mszarek]

Yup.

P.S.
Thanks for your reply!