Cheshire Cat Computing

Hi All,

I have hit a ice berg.

My current set up

ESX server 3.5
VCenter
50 VM's hosted
Nagios for monitoring


I want to monitor the network ( bytes sent , bytes received ) from these VM's and also on ESX server. So i understand Nagios only provide ping capability.

I am very new to these scripts , so i have very little knowledge , i want to monitor networking piece on my setup using Nagios.

If any one has implemented it , please do help me by providing the scripts and relevant pointers

Three ways to do it.

1) The check_vmware plugin will provide this functionality eventually, but does not yet do so due to complications. So you'd have to wait for that.

2) If you are using VSphere4, you can buy the Cisco virtual switch for ESX. This makes the ESX Virtual switch completely SNMP capable and so it can be monitored by MRTG or Nagios using the same methods you would use for a physical switch. This is probably the best way to achieve it - but there is a significant cost involved in the licenses.

3) With a bit of work, you can get this information from the OS. If you install nsclient/NC_Net or SNMP on windows, and SNMP or NRPE on Linux, you can query the network interface counters in the guest and then use MRTG and Nagios to monitor network traffic that way. This is how we do it. You need to make sure you are calculating the rate on the MRTG/Nagios server and not on the guest, though, else youll be affected by clock skew.

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

Hi Steve,

Thank you for quick reply,

Cant we modify the scripts which are used to monitor memory / CPU utilization to monitor Network ? , just a thought but if its not possible please do let me know.

Hi Steve,

So should i need to install NRPE on ESX server ? or just install NRPE on linux and monitor ESX server network interface.

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11

Hi Steve ,

I will stick on to your 3rd suggestion


3) With a bit of work, you can get this information from the OS. If you install nsclient/NC_Net or SNMP on windows, and SNMP or NRPE on Linux, you can query the network interface counters in the guest and then use MRTG and Nagios to monitor network traffic that way. This is how we do it. You need to make sure you are calculating the rate on the MRTG/Nagios server and not on the guest, though, else youll be affected by clock skew.

I will follow the below steps

a) Install NRPE on Nagios and then the daemon on the ESX server

b) Nagios will use check_NRPE plugin to query the interface on ESX server : For eg: the check_NRPE plugin will contact the NRPE daemon on ESX server and runs the Nagios Plugin

Question: Here how do i install the plugin for networking on ESX server ?? , with out network plugin , what method have you followed in your setup , so that i can follow the same

Thanks once again for your help steve

No, you should NOT install the NRPE daemon on the ESX server. This will not help.

You should install the NRPE daemon on the GUEST, not the ESX server. Windows guests can use NC_Net (nsclient) instead. Then you can use mrtg-nrpe or mrtg-nsclient for MRTG and the normal check_nt and check_nrpe for Nagios to query the agents.

If using NRPE you will need to install a NRPE plugin that obtains the network counters. This can be done from the output of netstat -i with a bit of scripting.

If you want to know the network bandwidth used by the guest, monitor the data from the guest (but only collect the total counters and do the rate calculation on your monitoring server)

If you want to know the total networking used by the ESX server, then instead monitor the port on the network switch that it plugs into. Much easier.

_________________
Steve Shipway
UNIX Systems, ITSS, University of Auckland, NZ
Woe unto them that rise up early in the morning... -- Isaiah 5:11