Cacti

I'm getting a weird error with the printer_supply.xml + Running data query [11]. + Found type = '3' [snmp query]. + Found data query XML file at '/var/www/html/cacti/resource/snmp_queries/printer_supply.xml' + Error parsing XML file into an array. + Found data query XML file at '/var/www/html/cacti/...

Could you give me any pointers on how to create a script (or edit one) to do this? I'm not very php savvy, but I'm sure I could figure it out.

I was wondering if anybody knew a way to create a threshold for the total bandwidth on a given interface (within a given time i.e. 1 week) instead of the current transfer speed. Any ideas? Thanks in advance.