Archive for December, 2007

VMWare Server Tips

VMWare Server on Linux (VMWare Server 1.04 on Ubuntu 7.10 Server)

– Physical Network Interfaces that will only be used by VMWare Guests:

Even though you may have a physical interface that a Host will not use, you need to set-it-up in /etc/network/interfaces. This will activate the network interface for the Host, which will only then allow the Guest system to utilize it. I am sure there may be a more elegant and secure way to accomplish this – I just haven’t had the time to do it myself. So, as a work around, I assign a static IP address, with a 32-bit subnet mask. This activates the interface, without providing a IP capabilities on the network.

There is probably a better/ more secure way to do this… let me know.


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My toolbox – an incomplete list:

MTR – Link Diagnostics
IPerf – bandwidth test
TCPTrack – track tcp connections per interface

An indespensbile trouble shooting tool is MTR. It is already a part of my favorite distro, Ubuntu. It combines the functions of ping and traceroute, and the info provided is excellent for diagnostics. More at: http://www.bitwizard.nl/mtr/

Just use it in place of ‘ping’. For example:


This will update your terminal display with:

– Packet Loss %

– Packets Sent

– Ping, Last Response Time

– Ping, Average Response Time

– Ping, Best Response Time

– Ping, Worst Response Tim

and my favorite

– Ping, Standard Deviation


The gold standard for bandwidth testing. In Ubuntu:

sudo apt-get install iperf

To use, you need one session running as the server, and another (or several) as the client.

A quick example:


iperf -s -D

this command will run the server


iperf -c -r -t 30 -P 3

this will connect to a server at IP, and perform a two-way test for 30 seconds each. The -P 3 is interesting, as it will run 3 parallel processes to get full bandwidth results. This is especially useful on a Windows system, and a single connection test won’t be able to pump out the full bandwidth capabilities.

The results are quite useful.


Quick reference to active connects on an interface.  Excellent on a proxy/ router to monitor who might be using to much traffic

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Check out http://www.lm-sensors.org  an open source project for embedded “sensors” for your Linux system.

I needed an easy way to check the CPU temperature for my new PC from the command line.  This is yet another great example of what open source has to offer.

On my Ubuntu 7.10 server, it was too easy:

sudo apt-get install lm-sensors

sudo sensors-detect

This will test your system to see which sensors should be installed.  Near the end, allow it to auto-add the kernel modules for you (make a note, in case you want to yank them later – for me, once I am done with the testing, I may remove them.)

Reboot your system

Once rebooted, type:


This gave me what I was looking for – CPU temp.  And a bonus – fan RPM.

I am sure there are many other uses for this – I have just scratched the surface.

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Install Webmin

Real quick – Webmin on Ubuntu 7.10.

Get Dependencies:

sudo apt-get install perl libnet-ssleay-perl openssl libauthen-pam-perl libpam-runtime libio-pty-perl libmd5-perl


sudo wget http://prdownloads.sourceforge.net/webadmin/webmin_1.380_all.deb

(or whatever version is latest – browse to the webmin site, and paste the link for the current version download)


sudo dpkg -i webmin_1.380_all.deb

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