[rrd-users] Re: RRD usage and disk I/O

[Michael Heiming]

Tobias Oetiker wrote:
> 
> Today Michael Heiming wrote:
> 
>  |
>  | Clifton Royston wrote:
>  | >
>  | > On Sat, Aug 04, 2001 at 12:53:17PM +0200, Michael Heiming wrote:
>  | > >
>  | > > Hello everyone,
>  | > >
>  | > > I'm currently developing a RRD/MRTG solution, my problem is, running
>  | > > MRTG/RRD from cron, that with about 20 machines at the moment and
>  | > > around 20 .rrd files per target, the load gets pretty high, while
>  | > > opening all those small files.
>  | >
>  | > Try switching to a smaller number of files per target with multiple
>  | > DSes per RRD file, this may improve performance.  (No guarantee, but I
>  | > think it will substantially reduce the number of disk writes and of
>  | > course directory accesses.)
>  | >
> 
> my tests show, that given your machine has about 250 MB ram you
> should be able to run rrdtool with up to 1000 rrd files updated
> every second ...
> 
> it is vital though that you are using LOCAL disk ... rrdtool does
> not work well across the network ... you will go down to maybe 20
> updates per second ...
> 
> chers
> tobi
> 
> --
>  ______    __   _
> /_  __/_  / /  (_) Oetiker, ETZ J97, ETH, 8092 Zurich, Switzerland
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Thx...for all your suggestions, I found my bottleneck today...:-)

I was just starting to much from cron, now I have only one script per
OS, that runs from cron, that itself calls all mtrg.conf files and
updates the .rrd.

Load is now below 1.00 (before > 15), with about 400 .rrd files, so
there should be no problems with even 10 x the .rrd files. I'll switch
to hw RAID1/U-160 SCSI anyway.

Thanks again

Michael Heiming

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