Locking Lubutu using a keyboard shortcut

Lubuntu is a promising lightweight flavor of Ubuntu that delivers a fresh and Lubuntu logosmooth experience even on old or ‘light’ hardware.

It still has some rough edges however (not many, this is the one I’ve discovered). Out of the box, the usual shortcut Ctrl+Alt+L doesn’t work (bug 1286686).

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Ubuntu Trusty Tahr 14.04 LTS on less-than-optimal hardware

Another time, another LTS release. It’s has been a while and our 12.04 LTS is now pretty old…time to switch to the new 14.04 LTS. Or maybe not.

The good news is that it’s completely possible to do an upgrade from 12.04 LTS to 14.04 LTS. The good news is this update can be partially done offline, using the 14.04 bootdisk, or and usb drive made with Ubuntu’s startup disk creator or your favorite bootdisk application. Another good news is that the in-place upgrade works, without the need of re installing everything. I am not a big fan of mayor number version upgrade, but it may come handy sometimes. Of course a good backup before upgrading is recommended and nearly mandatory. It may be necessary to re install some packages after the upgrade (I suspect this happens with third party packages). Unfortunately, the upgrade didn’t say which ones, or maybe I wasn’t paying attention. Continue reading “Ubuntu Trusty Tahr 14.04 LTS on less-than-optimal hardware”

Asrock ALiveNF6G-VSTA sound issue with Ubuntu Precise

Ubuntu precise is sometime unsettling at best. Audio won’t work with my old ALiveNF6G-VSTA. It used to be the reverse on Linux: old hardware would work, new hardware not always. Ubuntu Precise changed that altogether: old hardware isn’t working, and new hardware isn’t working either.

ALiveNF6G-VSTA motherboard. Photo courtesy of Asrock

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Playing with bluetooth GPS for fun and profit

I am recently fiddling with an old Bluetooth receiver to use it as a time source for my Arduino chrondot clock. Please note it’s already been done[wyolum.com] and an interesting graph of Chronodot drift is provided.
First of all I decided to get a good look at the NMEA stream coming out of the GPS unit.
It’s quite painless on recent Ubuntu (thanks westernwillow):

$>sudo hcitool scan
00:1C:81:55:1C:A1 iBT-GPS
$> sudo rfcomm bind /dev/rfcomm0 00:1C:81:55:1C:A1 1
$ ls -l /dev/rfcomm0
crw-rw---- 1 root dialout 216, 0 Nov 19 14:41 /dev/rfcomm0

Now we have a valid serial device we poll with minicom ($>sudo apt-get install minicom)
We have to change the serial device in minicom configuration $>minicom -sminicom bluetooth serial setup

The minicom bluetooth serial setup

than save and fire up minicom and you should see a stream of NMEA.

This would be an interesting step on itself to have an handy precise timesource using gpsd and ntp
Next step is to assert if the following is suitable [arduino.cc] for me.

Cryptswap and Linux assigning different devices letters to disk

I had this weird issue recently: I had a simple Ubuntu setup with cryptesetup and swap, and the crypt swap device (say /dev/mapper/mycryptoswap1) keept disappearing.
Caution: fiddling with cryptsetup and disk devices is dangerous for data and OS. I personally made a full backup on a separate disk and then umplugged it to be sure it wouldn’t be involved in any mishap.

Turns out is a little worse that that: Linux is changing the drive devices assignations (eg /dev/sdb /dev/sdg) at every boot under my nose. I did not notice at first because I am using UUIDs, so everything looked fine. Unfortunately my raw partition did not have any UUID.  Probably there’s a way to assign an UUID to a general partition, but I didn’t address this issue.
Having the disk changing its letter any time was the reason why the crypttab device wasn’t created a boot.  I was lucky: would a partition with valuable data be present in the other disk, it would be overwritten with encrypted swap data.
Continue reading “Cryptswap and Linux assigning different devices letters to disk”