User Mode Linux

Recently, we had the User-Mode Linux suite out of Debian, which included user- mode-linux, user-mode-linux-doc and uml-utilities package. We are happy that we were able to bring it back into the archvie quick, and hope to maintain it active.

For many who may not know about UML, here’s a discription from its website:

User-Mode Linux is a safe, secure way of running Linux versions and Linux processes. Run buggy software, experiment with new Linux kernels or distributions, and poke around in the internals of Linux, all without risking your main Linux setup.

User-Mode Linux gives you a virtual machine that may have more hardware and software virtual resources than your actual, physical computer. Disk storage for the virtual machine is entirely contained inside a single file on your physical machine. You can assign your virtual machine only the hardware access you want it to have. With properly limited access, nothing you do on the virtual machine can change or damage your real computer, or its software.

Most of the use cases mentioned here are achievable with Containers today. The big difference UML provides in, is with a separate kernel. UML is an implementation of Linux as an architecture of Linux itself. It supports x86 and x86_64 architecture. And given that it is the port of the kernel, you can do many of the tests and experiments of the regular kernel, safely inside a confined UML environment. As with other virtualization implementations, the limitation comes in if you are working on physical hardware.

[Read More]

Fully SSL for my website

I finally made full switch to SSL for my website. Thanks to [this](https://hblok.net/blog/posts/2016/02/24/lets-encrypt-tls-certificate- setup-for-apache-on-debian-7/) simple howto on Let’s Encrypt. I had to use the upstream git repo though. The Debian packaged tool, letsencrypt.sh, did not have enough documentation/pointers in place. And finally, thanks to the Let’s Encrypt project as a whole.

PS: http is now redirected to https. I hope nothing really breaks externally.

Categories: Debian-Blog General Computing  Tags: SSL https eff 

Leprosy in India

During my recent travel, I had quite a long layover at the Doha International Airport in Qatar. While killing time, I watched an interesting programme on the Al Jazeera network.

The program aired on Al Jazeera is Lifelines. This special episode I watched, covered about “Leprosy in India”. After having watched the entire programme, I felt the urge to blog about it.

First of all, it was quite depressing to me, to know through the programme, that the Govt. of India had officially marked “Leprosy” eradicated from India in 2005. As per Wikipedia, “Globally in 2012, the number of chronic cases of leprosy was 189,000, down from some 5.2 million in the 1980s. The number of new cases was 230,000. Most new cases occur in 16 countries, with India accounting for more than half.”

[Read More]

apt-offline backports for Debian Jessie

For Debian Jessie, the version of apt-offline available is: 1.5.1. This version has had some [issues](https://bugs.debian.org/cgi- bin/pkgreport.cgi?pkg=apt-offline;dist=unstable).

My very 1st backports is available in the form of [apt-offline 1.7 for ](https://packages.debian.org/source/jessie-backports/apt- offline)[Debian](https://packages.debian.org/source/jessie-backports/apt- offline) Jessie Backports. For Debian Jessie users, this should fix most of the issues.

Laptop Mode Tools 1.69 Released

Today is an auspicious day. For those who know (or follow) the Hindu religion will be familiar; Today is Maha Shivaratri![](/images/LMT-Maha- Shivaratri.jpeg)

On this day, It is great delight for me to be able to release Laptop Mode Tools, version 1.69

This release adds on many bug fixes and some enhancements. There is a new module (disabled by default) for cpuhotplug. The release tarball also includes a basic PolicyKit file for convenience, that packagers can use for the Laptop Mode Tools Graphical Configuration Interface. Apart from the policykit file, the graphical invocation script has been slightly fine tuned to work under pkexec and sudo. Some defaults have been tuned based on user requests - This should improve in situations where your External USB Mouse/Keyboard used to suspend after idle time periods.

[Read More]

Linux Power Savings 2016

Having moved to a new place, now at times, I also have to deal with power outages. As heat increases, the power outages will be much longer and more frequent. So much, that UPS and Power Inverters run out. Such are ideal times to measure idle power consumption for my laptop.

Here’s what my default (and idle) OS looks like. It should be standard to most “typical” users. Some minor odds could be apport, dnsmasq, and maybe, tor. Also, thanks to systemd, there are some native services which are now converted to socket activation based ones. There’s also Laptop Mode Tools for userspace power savings. But huge thanks to Intel’s work in making the kernel more power efficient. With things like Runtime PM and Intel P-State , we can now define, default and aggressive power-savings modes, helping conserve more power.

[Read More]

Linux IO + Memory + CPU Contention

I very recently met someone, and we had a good productive discussion on the features and (long standing) bugs of the Linux kernel. No doubt, Linux is the most featureful kernel in the market. Is also a lot appealing given its breadth of platform support.

Of that discussion we had, it led about Linux’s behavior in tighter stressed scenarios where there is a lot of contention among the core subsystems. From the conversation, I got the feedback that perhaps the issue is no more valid. My conclusion was I must have missed out on the fix because I haven’t really spent any Engineering Lab time in recent past.

[Read More]

Unbricking my Linksys

In trying to improve the WiFi service in my house, I recently dug out my old Linksys WRT54G Router. It is a 802.11 bg router, which can do 54 MBPS. Currently, I use a TPLink based router, with a DD-WRT community firmware, which claims is 802.11 bgn and can do 300 MBPS. The overall wifi signal isn’t adequate, so I thought of using the old router as a repeater.

The default Linksys VXWorks firmware does not have the bridging capabilities, so it was time to flashback, again, the dd-wrt image onto it (The last time I did, I eventually had to revert back to the stock firmware because my ISP claimed that the router was giving too many packet drops). Being an old device, and me being lazy, I did not pay much attention to the exact steps; and ended up bricking my router, wherein it wouldn’t give me the Management Console to flash a new firmware; nor would it give me the old VXWorks firmware interface. All it gave was a White Screen of Death and an active IP connection.

[Read More]

Lenovo Yoga 2 13 running Debian with GNOME Converged Interface

I’ve wanted to blog about this for a while. So, though I’m terrible at creating video reviews, I’m still going to do it, rather than procrastinate every day.

In this video, the emphasis is on using Free Software (GNOME in particular) tools, with which soon you should be able serve the needs for Desktop/Laptop, and as well as a Tablet.

The video also touches a bit on Touchpad Gestures.

State of Email Clients on Linux Based Platforms

I’ve been trying to catch up on my reading list (Thanks to rss2email, now I can hold the list longer, than just marking all as read). And one item from last year’s end worth spending time was Thunderbird.

Thunderbird has been the email client of choice for many users. The main reason for it being popular has been, in my opinion, it being cross platform. Because that allows users an easy migration path across platforms. It also bring persistence, in terms of features and workflows, to the end users. Perhaps that must have been an important reason for many distributions (Ubuntu) and service providers to promote it as the default email client. A Windows/Mac user migrating to Ubuntu will have a lot better experience if they see familiar tools, and their data and workflows being intact.

[Read More]
Categories: Debian-Blog Tools  Tags: gnome evolution Email