Überblick

In order to monitor a whole array of servers(or just your own homeserver), you can use Cacti. Cacti is an advanced rrdtool, which can be used in combination with netsnmp. This way you have a powerful monitoring tool, that can keep track of all kinds of data. The graphics can be imported into opensim, or machines can be manipulated using snmp and python scripts soon(with modrex).

Verfahren

Install RRDTools; Probably in your distro's repo, otherwise download with:

svn co svn://svn.oetiker.ch/rrdtool/branches/1.2/program

Check the instuctions how to build rrdtools

Install net-snmp; Probably in your distro's repo, otherwise download with:

svn co https://net-snmp.svn.sourceforge.net/svnroot/net-snmp net-snmp

Check the instuctions how to build net-snmp

Download cacti
Copy cacti into your Apache's www directory (/srv/http in this tutorial)
Add a cacti database into mysql, and add give a cacti-user all privileges for that database
Edit /srv/http/cacti/include/config.php, and fill in the mysql info
Create a crontab

crontab -e
# paste this line in, and save
* * * * * php /srv/http/serverstats/poller.php > /dev/null 2>&1

Login to cacti from the browser with admin,admin and change the password

Ok, this was the first part. Cacti is running, and you've installed all necessary software. Get yourself a nice cup of coffee if you wish, so we can proceed to the next level: Setting up snmp to return the stats that we so desperatly want...

Snmp comes in three flavors: version 1,2 and ...3 . Suppose you want to manage machines across the internet, you should check out version 3; which has user authentication and protection. For now, we'll use version 2.

Cacti Detailed View

Add this envpath to '/etc/profile'. Net-SNMP uses this to determin where the config file is

SNMPCONFPATH=/etc/snmp:/usr/local/etc/snmp

Create the file '/etc/snmp/snmpd.conf' and fill with this:

# rwuser: a SNMPv3 read-write user
# arguments: user [noauth|auth|priv] [restriction_oid]
rwuser rwos auth
# rouser: a SNMPv3 read-only user
# arguments: user [noauth|auth|priv] [restriction_oid]
rouser roos noauth .1.3.6.1.4.1.8072
# rocommunity: a SNMPv1/SNMPv2c read-only access community name
# arguments: community [default|hostname|network/bits] [oid]
rocommunity public .1.3.6.1.2.1.1
# rwcommunity: a SNMPv1/SNMPv2c read-write access community name
# arguments: community [default|hostname|network/bits] [oid]
rwcommunity private 127.0.0.1
 
syslocation "My Wicked OpenSimulator Datacenter"
syscontact "Your evil admin - evil@hell.org"
agentaddress tcp:161,udp:161

Restart the SNMP-Daemon, and test whether you can receive data(You should get a list of data here):

snmpwalk -v 2c -c private localhost

Go to Cacti, and modify the host called localhost(or add a new one, if none is there)

Some important settings: hostname tcp: 127.0.0.1 host template: Generic SNMP-enabled host SNMP version: 2 SNMP community: private

On top of the host, you should see some SNMP-information.
From here you need to add some graphing options. This can be done by adding things to Associated Data Queries(in the hostconfig), and then go to 'Create graphs for this host' (at the top). You will see some additional options here, that are linked to the data queries. Add graphing options here...
From now on, I suggest you get used to the cacti-interface by exploring all of it's settings

Next is the customizing of stats to reflect opensim specific information