[rrd-users] error in example code for hw in rrdcreate

[Norbert Preining]

Dear all,

I believe that the following example code in the manpage of rrdcreate is incorect:
        rrdtool create monitor.rrd --step 5m \
          DS:ifOutOctets:COUNTER:30m:0:4294967295 \
          RRA:AVERAGE:0.5:1:2016 \
          RRA:HWPREDICT:5d:0.1:0.0035:1d:3 \
          RRA:SEASONAL:1d:0.1:2 \
          RRA:DEVSEASONAL:1d:0.1:2 \
          RRA:DEVPREDICT:5d:5 \
          RRA:FAILURES:1d:7:9:5

The man page also says that the following dependencies of the rra-num are
required:
       ·   HWPREDICT rra-num is the index of the SEASONAL RRA.
       ·   SEASONAL rra-num is the index of the HWPREDICT RRA.
       ·   DEVPREDICT rra-num is the index of the DEVSEASONAL RRA.
       ·   DEVSEASONAL rra-num is the index of the HWPREDICT RRA.
       ·   FAILURES rra-num is the index of the DEVSEASONAL RRA.

In the above we have
	AVERAGE 	= 1
	HWPREDICT	= 2
	SEASONAL	= 3
	DEVSEASONAL	= 4
	DEVPREDICT	= 5
	FAILURES	= 6
Going through the above list:
       ·   HWPREDICT rra-num is the index of the SEASONAL RRA.
		should be: RRA:HWPREDICT:.....:3
		correct
       ·   SEASONAL rra-num is the index of the HWPREDICT RRA.
		should be: RRA:SEASONAL:...:2
		correct
       ·   DEVPREDICT rra-num is the index of the DEVSEASONAL RRA.
		should be: RRA:DEVPREDICT:...:4
		*incorrect* as 5 (above) links DEVPREDICT to itself
       ·   DEVSEASONAL rra-num is the index of the HWPREDICT RRA.
		should be: RRA:DEVSEASONAL:...:2
		correct
       ·   FAILURES rra-num is the index of the DEVSEASONAL RRA.
		should be: RRA:FAILURES:...:4
		*incorrect* as the 5 (above) links it to DEVPREDICT

So I believe that the correct way is
        rrdtool create monitor.rrd --step 5m \
          DS:ifOutOctets:COUNTER:30m:0:4294967295 \
          RRA:AVERAGE:0.5:1:2016 \
          RRA:HWPREDICT:5d:0.1:0.0035:1d:3 \
          RRA:SEASONAL:1d:0.1:2 \
          RRA:DEVSEASONAL:1d:0.1:2 \
          RRA:DEVPREDICT:5d:4 \
          RRA:FAILURES:1d:7:9:4

Is my interpretation of the man pages correct, or do I miss a detail here?

Thanks a lot

Norbert

--
PREINING Norbert                               http://www.preining.info
Accelia Inc.     +    JAIST     +    TeX Live     +    Debian Developer
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