[HOWTO] RESIZE existing RRAs of existing RRDs

warenet · Posted: Mon Mar 27, 2006 11:51 am Post subject:

ooops.... thanks.

warenet · Posted: Mon Mar 27, 2006 5:09 pm Post subject:

Now this maybe a silly question...

But does it make sense to remove the other RRAs? Is it even possible?

It seems it makes sense to do this. I have a number of charts that combine multiple RRDs and right now I'm getting 8 graphs for some reason. I guess it maybe because the RRAs don't match on the other week, month, year collections.

gandalf · Posted: Tue Mar 28, 2006 12:49 pm Post subject:

No silly question. cacti will use the rra's related to the Data Template to define the number and timespan of those graphs. AND, theses rra's are taken when defining the rrd file
Reinhard

warenet · Posted: Sun Apr 02, 2006 12:57 am Post subject:

So can I just resize the other RRAs to 0?

gandalf · Posted: Sun Apr 02, 2006 6:04 am Post subject:

I did not try on my own. But you may of course give it a go. Not sure on the behaviour of rrdtool when trying to consolidate data to some existing rra with size=0.
Reinhard

warenet · Posted: Sun Apr 02, 2006 10:45 am Post subject:

Ok -

I suppose it isn't really affecting anything, as in Cacti is eing smart enough not to use the consolidated RRAs for the week, month, year graphs after applying the new ZLVM data source templates?

Is there any reason to not apply these templates to the default templates, etc? I have several hundred data sources and it would seem least time consuming to apply at the "data template" level.

Best,

gandalf · Posted: Sun Apr 02, 2006 12:29 pm Post subject:

warenet · Posted: Mon Apr 03, 2006 10:54 am Post subject:

I'm a bit confused by your response...

Is it "ok" to change the default template definitions, or even the default RRA definitions?

Or do you recommend against that.

I'm certainly open to a patch so that I don't have to delete/add the 0 length RRAs before creating new data sources

warenet · Posted: Sat Apr 08, 2006 10:32 am Post subject:

As a follow-up, I've switched to the "ZLVM" RRAs in Data Templates for a number of graphs.

I've also resized virtually all of my RRDs except for CPU and other metrics where long term high resolution isn't needed.

However, all my "yearly" graphs are failing.

I get this error in the httpd error logs:

gandalf · Posted: Sat Apr 08, 2006 10:50 am Post subject:

Please select the wrench next to the failing graph and post the whole rrdtool graph statement
Reinhard

warenet · Posted: Sat Apr 08, 2006 11:11 am Post subject:

gandalf · Posted: Sat Apr 08, 2006 1:48 pm Post subject:

This statement seems to be ok (apart from the fact, that 95th Percentile and Totals are wrong). Please post a screenshot of the graph.
But be aware, that my last posts are only workarounds and no real solution. RRAs with 0 data points are not that usual. This may confuse the cacti-built-in calculations. But I don't suppose that a bug report against this will have great success.
Reinhard

warenet · Posted: Sun Apr 09, 2006 1:17 pm Post subject:

Not sure what graph I can post?

Its failing to generate the graph at all.

?

TIA

gandalf · Posted: Sun Apr 09, 2006 2:00 pm Post subject:

Sorry for confusing you. As the rrdtool graph statement looks ok, I assumed that the Graph would display but the numbers were wrong. But several posts above, you posted the error from httpd's log, so this is now clear to me.
Obviously, some internal calculation went wrong. This is perhaps due to the "strange" nature of my RRAs. You may post this (with a reference to this post) at http://bugs.cacti.net stating what you're aiming at.
Sorry to not being of more help
Reinhard

warenet · Posted: Tue Apr 18, 2006 6:48 pm Post subject:

Thanks -

I'll try that as well.

On another note - as you know I've changed the RRA description for certain data templates to yours.

I'm curious how I can now create new graphs. I've tried temporarily removing all the RRAs except the yearly one, but this doesn't seem to have the desired effect.

I wind up with a single RRA, but its a bit odd: