snmp versus /proc

[Les Mikesell]

On Sun, 2005-08-21 at 09:12, Timothy Murphy wrote:
> > 
> > Monitoring systems often monitor many servers running
> > different OS's and other devices like routers and switches.
> > Snmp values are available over the network with fast udp
> > requests.  /proc is only available  on the local host and
> > only on Linux and similar OS's.
> 
> I did think of that.
> However, rrd seems generally to be used
> to create a graphic presentation available on the web,
> so I assume that could be viewed on other machines on the LAN.

Yes, but when you are managing a lot of machines you don't
want to have to look at web pages from different servers
to view each one, you want to combine similar graphs from
multiple servers on the same page so you can easily spot
something that is wrong or different.

> But I don't really know what I am talking about.
> What struck me was the complication of setting up snmp
> (I haven't succeeded in working out how to get v3 running yet),
> compared with the simplicity of just getting eg the CPU temperature
> from /proc and converting it to the format required to update the rrd
> with perl, or whatever.

Lots of devices already have snmp working and on Linux you
just need to install the rpms and remove the config entries
that keep anything from talking to it.

> I'm just surprised none of the examples I looked at
> seemed to do anything as simple as this,
> and I wondered if I was missing something.

Look for examples that graph router interface statistics
or network/memory/cpu use on Windows boxes.  These are
both very simple with cacti doing the rrd/snmpget setup
for you - and things with no /proc access.

-- 
  Les Mikesell
    lesmikesell at gmail.com