[rrd-users] Please help me understand this

Simon Hobson linux at thehobsons.co.uk
Fri Oct 15 14:30:37 CEST 2010

Marklar Inc. wrote:

>I dont really understand the answer. What is the explaination that 
>the graph plots its first value on sunday, when the dump clearly 
>says that it is monday?

The times you will see in a dump will be the END times of time 
periods. RRD Tool does not work with points in time, only with time 
periods and rates.

So if you have a dump that shows a value for 1am on Monday, that 
actually refers to a timeslot of 1am Sunday to 1am Monday - assuming 
+1 as a timezone. Plus, your graph statement asks for a graph from 
Sat Oct  2 13:00:00 BST 2010 to Fri Oct  8 23:14:51 BST 2010 - so you 
actually got what you asked for.

Your last update was at Fri Oct  8 13:00:00 BST 2010 which means the 
timeslot from 1am Fri to 1am Sat is not complete, so no data exists 
for graphing after 1am Friday.

You asked for a graph from Sat to Fri, and apparently got a graph 
showing data from Sunday (there was no earlier data so there should 
be blank pixels for that) through to Friday 1am (there is no later 
data and there should be blank pixels there as well).

See Alex's tutorial on normalisation and consolidation at 

Simon Hobson

Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed
author Gladys Hobson. Novels - poetry - short stories - ideal as
Christmas stocking fillers. Some available as e-books.

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