Matlab – tips and tricks

Would like to ensure all additional MATLAB support packages are installed on the share location:

1. launch matlab as “root” user
2. find out the current support package root (default is homedir:


3. set it to a share location:

4. To change the add-ons installation folder
On the Home tab, in the Environment section, click Preferences > MATLAB > Add-Ons.
5. To install support packages, on the MATLAB Home tab, in the Environment section, click Add-Ons > Get Hardware Support Packages.



The USB Webcam does not work in RHEL6 due to some libraries, but work fine in RHEL7.

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Linux 101 – crond

Always remember to put full path of the scripts or commands to be run in crond.

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cfengine2 segfault – culprit ipv6 in kickstart

I had been troubleshooting cfengine segfault for days and finally found the issues:
Network setup in the kickstart %post had enable networking_ipv6, which confuse cfengine

It was a broken kickstart since long time ago, and the workaround was rerun “cfagent” again. Not a very good workaround.

Anyway, by copying and mimic some necessary changes in %post for network setup fixed the issue!

This is the final solution that I had done in my kickstart.cfg:

network –bootproto=dhcp –onboot=on –noipv6

to ensure ipv6 will not be activate during or after kickstart.


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Basic steps to setup pulseaudio (DisplayPort output) in Linux

Here is some basic steps (and reminder to self):1. install pulseaudio-utils
# yum install pulseaudio-utils
2. Check which output to can be use:
# pactl list

** find the output you need, the 1 I am outputing is "output:hdmi-stereo-extra2+input:analog-stereo"
** you might need to start "pulseaudio -D"

3. Set the default output:
# pactl set-card-profile 0 output:hdmi-stereo-extra2+input:analog-stereo

4. To make the changes permanent, append/insert/edit /etc/pulse/
set-card-profile 0 output:hdmi-stereo-extra2+input:analog-stereo

And this should be able to play sound output to DisplayPort.

More info about:

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How to plot sysstat (SAR) into a beautiful graph?

In the past, I had been using kSar to quickly plot graphs from sar files that I had collected from the systems, but I would really prefer a system that it can consolidate all the sar reports from various systems and generate beautiful graphs to do performance analysis.

I know there are tons of tools out there that can do that : Nagios, Sensu, Shinken, Cacti, just to name a few, but all these is generating the graphs base on the data it collected instead of the sysstat sar file located in /var/log/sa.

I still haven’t find any that do that, but the closer I found is SarGraph, which will run a periodic sar command remotely to systems and keep the data on the sargraph servers. Currently it only give 4 performance metric: CPU, Memory, Swap and Run-Queue Size.

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Oh yes! Got the internal workstations to work with internal RH Satellite

After a few weeks of testing and experimenting, finally found out the issue of the setup:some repos were not enable by default

Now, I had figure the issue and put the changes into cfengine (yes I know is old school) and will also include in ansible playbook (WIP).

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Am I good in anything at all?

I don’t know how to cook except fried egg, and boil water (for instance noodles and 3 in 1 coffee/tea).
I don’t know how to play any music, can’t even sing without hurting others’ eardrums.

I don’t know how to sew – can’t even sew back a button on the shirt.

I don’t know how to …

What am I good in doing? Maybe only 1 thing I am really good in – being myself!

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