# [rrd-users] VDEF MINIMUM

Oliver oliver341 at live.co.uk
Tue Aug 9 11:53:47 CEST 2011

```I'm seeing more marked differences in VDEF MINIMUM now.

m at n:~\$ rrdtool graph testing.png -s end-10000
DEF:noise=noise.rrd:noise:AVERAGE VDEF:min=noise,MINIMUM PRINT:min:%.1lf
0x0
5.2
m at n:~\$ rrdtool graph testing.png -s end-25000
DEF:noise=noise.rrd:noise:AVERAGE VDEF:min=noise,MINIMUM PRINT:min:%.1lf
0x0
6.9

So the minimum recorded value in the last 10,000 seconds is 5.2 and the
minimum recorded value in the last 25,000 seconds is 6.9.

Any help appreciated.

Thanks,
Oliver.

-----Original Message-----
From: Oliver
Sent: Thursday, August 04, 2011 11:25 PM
To: rrd-users at lists.oetiker.ch
Subject: [rrd-users] VDEF MINIMUM

Hi,

I'm slightly confused about the output I get from the VDEF MINIMUM function
(RRDtool version 1.4.5, if that's relevant).

Specifically:

m at n:~\$ rrdtool graph test.png -s end-10000 DEF:noise=noise.rrd:noise:AVERAGE
VDEF:min=noise,MINIMUM PRINT:min:%.1lf
0x0
6.1
m at n:~\$ rrdtool graph test.png -s end-15000 DEF:noise=noise.rrd:noise:AVERAGE
VDEF:min=noise,MINIMUM PRINT:min:%.1lf
0x0
6.2

What I can't understand is how the minimum value recorded within the last
15,000 seconds can be higher than the minimum value recorded for the last
10,000 seconds, given that the last 15,000 seconds is a superset of the last
10,000 seconds.

I'm probably misunderstanding the VDEF facility somehow. Can anyone shed any