Category Archives: IT

Your Motorola MG7310 wireless router performance sucks? Try this…

In order to avoid paying monthly fees to cable companies, I chose to buy my own router, a Motorola 7310. The specs looked acceptable for a decent price but the performance out-of-the-box revealed itself horrible in our building where there are tons of other WiFi routers.

A couple of changes to the standard configuration helped make the performance acceptable, so if you have this router and your bandwidth/latency is not good enough, you might want to try that.

Log in to your router and click on the “Advanced” button.

Then click on the “Wireless” tab. Change the channel to “6” and the bandwidth to “20 Mhz” and click on “Save”


Next click on the “WMM” sub tab and turn off “Power Save Support” and click Save.


In the “Advanced” sub tab, disable “OBSS coexistence” and save

I hope these changes will increase your performance, but although I work for one of the best Enterprise WiFi companies, I am not a networking guy and YMMV depending on what type of building you are in and what is the density of networks.

Migration to my own email server

After the revelation of the mass surveillance programs used by government agencies from various countries and given the unhealthy amount of information that I provided to Google, using services such as Gmail, Google Maps, etc, I decided already in mid-2013 to take my privacy back.

I already had setup my own calendar (calDAV) and contact list (cardDAV) using Baikal on my own server and Davdroid. However, in the past couple of weeks, I finally completed the last point I still wanted to implement: migrate away from Gmail to run my own email server. I followed this excellent setup guide to setup Postfix, Dovecot & Co and am now reachable at herve at hmarcy.com. I moved all my Gmail emails with Thunderbird by copying the IMAP files and everything works just fine. I did not receive any spam so far. If you have a little bit of experience with Linux system administration, I strongly advise you to give it a shot, because the tutorial is really easy.

If you feel comfortable using Gmail or other free email services based in the US, maybe this video will help change your mind.

This is also of course valid for non-US citizens/residents, as the US government shares a lot of information with foreign government agencies. The Electronic Frontier Foundation also published pretty much everything you need to know about the scale of the NSA spying activities at https://www.eff.org/nsa-spying

Do you want to make the content of your emails safe and (fairly) unreadable by a third party, be it Google or anyone else? Encrypt them conveniently with GPG, Thunderbird & Enigmail. The Enigmail quick start guide will help you to do so!

Software-Defined Datacenter ? No thanks, I prefer Open and Standardized

I recently did a presentation at HP Discover in Barcelona, Catalonia, called Red Hat’s vision for an open-hybrid cloud (the slides are also available). When preparing the presentation, I thought at first calling it “Red hat’s vision for a Software-Defined Datacenter”. The term “Software-Defined Datacenter” (SDDC), first coind by VMware, has become extremely popular in the IT industry in the past months. There are very few parts of the datacenter that cannot be “software-defined” anymore. The first element was the Software-Defined Networking (SDN), then followed by Software-Defined Storage (SDS), Software-Defined Computing (SDC),  that led to the SDDC.

However, during the preparation of my session, I stepped back a little and thought about what this “software-defined” trend was about and I asked myself this question: what datacenter today runs no BIOS ? no hypervisor ? no operating system ? no application server ? and no application ? None, of course. Why ? Because a datacenter has always been defined by software ! The difference with today’s IT industry are two factors that are driving efficiency: openness and standardization.

  • What is software-defined networking ? It is about taking a standard x86 server, connecting it to the network, and, through software, make it a controller for the network environment using open protocols.
  • What is software-defined storage ? It is about taking standard x86 servers and using the capacity of their internal disks and, through software, put their capacity at the disposal of clients through open access protocols.
  • What is software-defined computing ? It is about taking standard x86 servers and consolidating hundreds of servers virtualizing the standard x86 processors instructions.

A software-defined datacenter is nothing but an open, standardized datacenter.

But what about the cloud ? To me, cloud is the automation layer that will manage resources on top of this infrastructure. Be it public or private, a cloud creates an automated way to provision services by offering a service catalogue to users through a self-service portal.

The question is now with whom do you want to work to implement this open, standardized datacenter ?

After having freed yourself from proprietary, hardware-centric and purpose-built hardware, what would be the point of locking yourself again with a software vendor ? Openness on the infrastructure side can only be matched by openness on the software side, and Free and open-source software (FOSS) is the key for you to keep the control on your environment, and especially have the choice of different vendors to choose from. Open protocols are key to provide access to all part of this type of infrastructure, and that is the beauty of FOSS: there can be no proprietary protocol, as the way applications talk to each other is known by everyone. No secret sauce, no voodoo magic and no “trust us, everything is going to be fine”, just plain openness, from which you can only benefit.

Who do you think can help you building this open standardized datacenter ? In terms of vendors, think of one who’s been standardizing Unix platforms onto standard x86 servers with an open-source operating system for the past 20 years. Think of a vendor that provides storage solutions based on x86 servers and open protocols. Think of a vendor heavily involved in all of OpenStack’s modules, including Neutron, that manages networking. This is what Red Hat has been doing for the past 20 years: opening and standardizing.

The future might bring surprises. The trend toward ARM-based servers, SoCs, and hyperscale computing might create new silos of technology. Software-based storage on top of x86 servers will probably co-exist with fibre channel SANs for some time. But as long as your environment is as open (in hardware and software) and as standardized as possible, you are in good hands. But do not blindly trust vendors who claim they are open. Trust the open-source communities and the vendors who contribute the most to them.

CyanogenMod installed on my Galaxy SII using Fedora

As I am on vacation with some time to kill, I decided to free my Samsung Galaxy SII from all the Samsung crapware and install an open-source version (GPLv2 and Apache 2 licenses) of Android on it : CyanogenMod. Here is how I did it, using Fedora 17 only.

I do not take any responsibility for what you do with your device. YMMV with your Android version and hardware model. This kind of operations voids the warranty of your smartphone and may damage it irreversibly. (But, hey, it’s fun 🙂 )

First, let’s compile and install the tool that will help us to root our Android mobile phone “Heimdall”. We start by installing the development tools and needed libraries.

# yum -y install “Development Tools”
# yum -y install libusb1-devel

Then we compile and install the actual program

$ git clone git://github.com/Benjamin-Dobell/Heimdall.git
$ cd Heimdall/libpit
$ ./autogen.sh
$./configure
$ make
$ cd ../heimdall
$ ./autogen.sh
$ ./configure
$ make
# make install

After that, we download the tool that will root our Android phone: ClockworkMod Recovery, our CyanogenMod operating system as well as Google Apps.

$ wget http://cmw.22aaf3.com/c1/recovery/recovery-clockwork-5.5.0.4-galaxys2.tar
$ md5sum recovery-clockwork-5.5.0.4-galaxys2.tar
364315cb9a499d50638d05b93bb44422  recovery-clockwork-5.5.0.4-galaxys2.tar

$ wget http://download.cyanogenmod.com/get/jenkins/4627/cm-9.0.0-RC2-galaxys2.zip
$ md5sum cm-9.0.0-RC2-galaxys2.zip
ee62fd69d305d8af79e65cd7c8bdd459  cm-9.0.0-RC2-galaxys2.zip

$ wget http://goo.im/gapps/gapps-ics-20120429-signed.zip
$ md5sum gapps-ics-20120429-signed.zip
7c524e1e078164f681e0aa6753180b2c  gapps-ics-20120429-signed.zip

We then extract the following file

$ tar -xvf recovery-clockwork-5.5.0.4-galaxys2.tar

The extracted file is a kernel image called “zImage” that we will boot on later on

Put the CyanogenMod as well as the GoogleApps in the root directory of your SD card, then, let’s get rid of the Samsungoid ! This is also the right moment to backup your data and configuration, in case anything goes wrong.

Power off the Samsung Galaxy S II and connect the microUSB to the computer but not to the Samsung Galaxy S II.
Boot the Samsung Galaxy S II into download mode by holding down Home & Volume Down & Power while connecting the microUSB to it.
Change the directory back to where the previously extracted zImage file is and execute the following command

# heimdall flash –kernel zImage

A blue transfer bar will appear on the phone showing the kernel being transferred. But, unlike CyanogenMod’s documentation mentionned, my Galaxy SII did not reboot automatically. I tried to boot it by pressing on the power button on the right side, but it did not work. The only thing that worked was starting the phone by pressing on Home & Volume Up & Power at the same time, until the ClockworkMod Recovery booted.

In ClockworkMod Recovery, select the following options

“Wipe data/factory reset” then “Wipe cache partition”
“Install zip from sdcard” -> “Choose zip from sdcard” and choose first CyanogenMod and redo the operation for the Google Apps zip file

Once the installation has finished, select “Go Back” to get back to the main menu, and select “Reboot system now” and CyanogenMod should boot as it did for me.

So far, the user experience is much better and my phone is way faster than it used to be. The process was not as straightforward as I described it here and I had a couple of “interesting” moments when the Galaxy did not boot as expected, but I hope it will make your switch to a freer operating system smoother.