Things n' Stuff Thoughts about the universe in general

More interesting things will probably come up during the day, but so far I liked Google’s idea (also see a link from google.com).

צילום בלילה עם פלאש:

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Its called ldapvi, and its just about what you’d expect with that name :-). The author would like you to think about it as vipw for your LDAP based authentication, and in addition to a few command line option it really isn’t much more then that (UI-wise):

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Nvidia Optimus is a neat solution to the problem of power consumption vs. 3D performance in notebook computers – the computer comes with two graphics chips, an “integrated graphics package” – the Intel GMA embedded graphics and a “discrete graphics package” – the Nvidia chip. The setup works by running your normal windowing UI on the integrated graphics, only powering on the discrete graphics when you want to play a 3D game or something like that.

Recently I had the fortune to work on a Lenovo T420 laptop¹ that has this setup, and it works very well on MS-Windows with the Nvidia Optimus driver – you get battry life around 10 hours with the 9 cell battery.

Unfortunately I spend most of my day in Linux and because Nvidia does not support Optimus on Linux, you have the poor choice of either running everything on the Nvidia chip – decreasing battery life to around 4 hours if you’re careful, or disabling the Nvidia chip completely.

The solution comes from the Bumblebee project – a software suite to handle the switching between the Nvidia discrete graphics and the embedded Intel chip.

The setup is pretty simple to understand (though I suspect under the hood there are many problems to be solved): A service runs and waits for users to ask for 3D accelerated graphics. When a user starts a program using the special command optirun, the service loads the Nvidia driver, starts an X server using the discrete graphics (with the display disconnected from the actual screen) and runs the specified program on that “background” X server. Then it copies the visuals from the program that is rendered using the discrete graphics to a window on the main X server. When the program terminates, the service closes the secondary X server, removes the driver and powers down the graphics card – putting us back into the ~10 hours battery life.

The Bumblebee software had some problems in the past, but the current version – 3.0 – looks very good. There are a few seconds of delay when you launch the application (setting up the driver and X takes some time), but performance is about what you’d expect when running directly on the hardware. All this without any configuration – that is if you are running on the stable Ubuntu version.

As I can’t leave well enough alone, and whenever someone says “alpha”, I say – “I wants”, I’m running the current Ubuntu 12.04 alpha (which is not so bad – due to be released in a couple of months, it works very well). And of course Bumblebee doesn’t work properly here.

So this is what I had to do to get it running:

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1. with an amazing 1600×900 screen, what they call “HD+”. Truly a work of art [↩]

In my company we (still) use an Active Directory domain controller to manage central authentication¹, which is not set up very well – no SSL and the Kreberos setup is not done properly. This makes gives much trouble to modern Linuxes (e.g. not Ubuntu. yes – I’m looking at you Shuttleworth.)  such as Fedora, as Fedora have done away with NSS/PAM based LDAP authentication and instead relies on SSS – which I have yet managed to get working or even find a tutorial on how to set it up properly.

So if you still want to authentication your Fedora installation against the company’s Active Directory – and can’t/won’t rely on Winbind’s notably flaky behaviour, you can always install NSS/PAM ldap authentication manually. Unfortunately its not as easy as it sounds, and as I learned the hard way – one must pay careful attention to SELinux. So here’s the recipe:

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1. there are a lot of MS-Windows workstation, so it kinds of makes sense – but we are planning to phase it out in favour of OpenLDAP, so don’t worry about it [↩]

The purpose of this exercise is to convert a hand written note – such as your signature – to high quality digital files that can be used to embed “hand write” into documents – such as when someone asks you to fax them a “signed” copy of the PDF they emailed you. You’d be surprised how often that happens around here.

Required Ingridients:

• A computer with The GIMP installed
• Your handy smart phone with a 5MP or better camera
• A good pen and paper.

So anyway, here’s the process from top to bottom, with pictures:

1. Sit down at a proper table, and using a good black heavy-line pen¹ on a white clean high-density paper, write what you need to write – slowly and deliberately but without pauses. Try not to smear the ink so you get clean continuous lines, otherwise the quality suffers a lot.
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1. in this shot I used a 0.7 permanent marker – which is just overdoing it – probably any 0.7 pen will work [↩]