What is the best strategy to count the events

Hi,

I want to define an rrd to count the virus detected in my email.

Every 5 minutes I update the rrd, usng an exact timestamp and the number
of viruses detected in the last 300 seconds period.

What should I do for the periods with no virus? Do an update with the
value 0 or do nothing?

And how to define the DS and the RRA so I can have the total number of
viruses found by 2 hours slots, byfor weekly, monthly, yearly graphs?

Thanks in advance,

Olivier
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