Jun's Scribbles

Flashing bios using a usb drive

2013-05-16T20:54:00.003+12:00

If you are like me where most PC run's linux and has no optical drive. I saw the following steps around the net to be helpful.

Get the bios update iso

Get 'geteltorito' and extract the boot image from the iso

$ wget 'http://www.uni-koblenz.de/~krienke/ftp/noarch/geteltorito/geteltorito.pl'
$ perl geteltorito.pl biosupdate.iso > biosupdate.img

Copy the image to the usb thumdrive

$ sudo dd if=biosupdate.img of=/dev/usbthumdrive bs=512K

Small Android stick (mk808b) mini review

2013-04-13T23:06:00.000+12:00

Me and my mates at the office just bought one of those Android mk808b. Its dirt cheap, so we gave it a try.

So far its been pretty good. I plugged to an existing TV with hdmi and I can now use the TV for browsing, watching streaming videos and skype. Since I am a Linux user I got a UVC compliant webcam, which works on this device as Android uses a Linux kernel. So with little a fraction of a cost I was able to turn my old TV into what they call a smart TV (didn't like the idea of smart tv, never bought one). Normally before this TV had a laptop plugged into it, now Android stick pc replaced it.

Pros (would not elaborate on it too much, lots of people have put heaps of comments around the web)

Low cost. These cost about $50-90 around the net. Also as part of the low cost, is that you can use your existing TV as long as it has a hdmi input.
Small and low power. This comes with a USB adapter. However I had mine just plugged into my xbox 360 usb port, even way better.
Newer firmware comes pre-rooted. Mine is already rooted.

Cons

Clearly Android is for touch. I bought the bundled air mouse, you can also use normal usb mouse and keyboard. However the experience is not as nice, same experience as running the Android developer emulator on your PC. You can only use apps that will run with single touch operations or single touch swipes. Youtube, web browsers, skype, angry birds will be ok. However google maps (no pinch zoom, so I don't know how to zoom out.. zoom in can done via double tap). My idea was to get my tablet back from my kids, however this clearly an inferior experience for them. So it kinda did not work, and now they can tell me to use my stick Android and they will use the Android tablet. Plan back-fired.
Its not well polished. This can leave a poor impression on Android for users having this as their first Android device. Though this is Jelly Bean, its really far away from the experience you have from a Nexus 4, even from a 2 year old Asus Transformer.
It seems the cpu stays at 1 ghz no matter what the load is. Now sure why I haven't played with the governor yet. So it doesn't go 1.6ghz or drops down to 200-400mhz.
The out display seems to be 16 bit (not sure but it looks like it), also always resets to 720p after every boots up. I read that you will need to reflash so it renders the color in 24/32 bit. Again doesn't look that good, but not too bad if don't look for image issues (gradients and dithers).
The air mouse is sensitive to interference. I am still running on 2.4 wifi, I have not much other devices and neighbors are far away. However you can see during real big burst of traffic the air mouse is getting cut off as seen by the lag.

So the android stick PC is not really dirt cheap as it seems to be. This is probably not a good first Android device. However is a great bargain if. You have a TV that you want to run some basic computing needs (web browsing, video calls, streaming video, music playing). You can upgrade the TV and replace an aging laptop that used to perform those computing needs.

In order for the stick PC to have a great experience you need to buy a good input device. Which would now increase the cost. It also doesn't have a screen, no battery, etc. So a Nexus 7 would probably be cheaper as a first good Android device.

Angular.js for ajax CRUD

2012-08-26T22:37:00.000+12:00

Its been a busy weekend, not in terms of coding though. Just did some quick coding now. This is now a book-markable ajax CRUD talking to conventional REST/JSON backend.

//app.js

angular.module('ratewatcher', ['ngResource']).
 config(function($routeProvider) {
  $routeProvider.
   when('/lenders', {controller:LenderListController, templateUrl:'lender-list.html'}).
   when('/lenders/new', {controller:LenderCreateController, templateUrl:'lender-detail.html'}).
   when('/lenders/:id', {controller:LenderEditController, templateUrl:'lender-detail.html'}).
   otherwise({redirectTo:'/lenders'});
 }).
 factory('Lender', function($resource) {
  return $resource('/lenders/:id', {id: '@id'}, {});
 });

//controllers.js

function LenderListController($scope, Lender) {
  $scope.lenders = Lender.query();
  
  $scope.remove = function(lender) {
   lender.$remove();
  }
}
  
function LenderCreateController($scope, Lender) {
  $scope.save = function() {
    var lender = new Lender({id: 0,
     name: $scope.lender.name, 
     category: $scope.lender.category, 
     url: $scope.lender.url
    });
    
    lender.$save();
  };
}

function LenderEditController($scope, $location, $routeParams, Lender) {
 $scope.lender = Lender.get({id: $routeParams.id});
 
  $scope.save = function() {
   $scope.lender.$save();
   $location.path('/');
  };
}

I thought the scala backend was really concise, but it turns you can also make the front end javascript just as concise. Coupled with bootstrap css and basic html, this seems pretty good.

Suggested readings:
http://www.angularjs.org/ - Wire Up a Backend example
http://docs.angularjs.org/api/ngResource.$resource
http://jsfiddle.net/johnlindquist/qmNvq/
http://docs.angularjs.org/api/ng.$route

Angular.js my first few mins impression

2012-08-23T20:52:00.001+12:00

I have been looking at Javascript frameworks. I have experience in GWT and lately trying to learn ember.js. So far ember.js is really powerful, but the docs is not that great. Ember.js has made a lot of changes and the only way to learn it seems to be to read the code/api. Since my javascript is not that good, it was taking me a bit of time to learn the magic of ember.js. This lead to me look again a bit, I found angular.js because it was in google's CDN api.

Having read the watch and read the front page of angular.js it seems to be just as powerful as ember.js. Its got bi-directional binding, a template engine, name spaces. The terminology they have is FP (ala Scala). They have apply, future promise. So gave a try.

function LenderController($scope, $http) {
 $scope.lenders = [];
 
  $scope.all = function() {
    $http.get('/lenders').success(function(data) {
      $scope.lenders = data;
    });
  };
}

<div class="span10" ng-controller="LenderController">
    <table class="table striped">
        <tr> 
            <th>Name</th><th>Category</th><th>Url</th> 
        </tr>
        <tr ng-repeat="lender in lenders"> 
            <td>{{lender.name}}</td> <td>{{lender.category}}</td> <td>{{lender.url}}</td> 
        </tr>
    </table>
    <a href="" ng-click="all()">fetch all</a>
</div>

Pretty short and direct code for fetching from json/rest backend and displaying it on the view. I think Angular.js is powerful and yet easy for a newbie to pickup. That is my first few mins impression of it.

Ruby was shiny before compared to Java, Tcl and Perl. Isn't as shiny when its beside Scala now.

2012-07-12T20:27:00.000+12:00

Just looking at Ruby again. My first encounter with Ruby like most people is through ROR, it was a few years back (era 1.x or maybe before that). It was a very nice language and at that time, it wasn't that popular. I did however convince a colleague of mine to push ROR with the help of Bruce Tate's From Java To Ruby book. He was successful in getting ROR into a Java EE environment. I had a quick glance of Ruby again today and in tutorial there was this code:

class MegaGreeter
  attr_accessor :names

  # Create the object
  def initialize(names = "World")
    @names = names
  end

  # Say hi to everybody
  def say_hi
    if @names.nil?
      puts "..."
    elsif @names.respond_to?("each")

      # @names is a list of some kind, iterate!
      @names.each do |name|
        puts "Hello #{name}!"
      end
    else
      puts "Hello #{@names}!"
    end
  end

  # Say bye to everybody
  def say_bye
    if @names.nil?
      puts "..."
    elsif @names.respond_to?("join")
      # Join the list elements with commas
      puts "Goodbye #{@names.join(", ")}.  Come back soon!"
    else
      puts "Goodbye #{@names}.  Come back soon!"
    end
  end

end


if __FILE__ == $0
  mg = MegaGreeter.new
  mg.say_hi
  mg.say_bye

  # Change name to be "Zeke"
  mg.names = "Zeke"
  mg.say_hi
  mg.say_bye

  # Change the name to an array of names
  mg.names = ["Albert", "Brenda", "Charles",
    "Dave", "Englebert"]
  mg.say_hi
  mg.say_bye

  # Change to nil
  mg.names = nil
  mg.say_hi
  mg.say_bye
end

It's nice and concise, however it doesn't stand out as much as before. My comparison was Java, Tcl and Perl a few years ago. I then did a quick copy and paste, translated it to Scala.

class MegaGreeter(var names: Any = List("World")) {
 
  def say_hi {
    names match {
      case null => println("...")
      case listOfNames: List[String] => listOfNames foreach (n => println("Hello " + n)) 
      case _ => println("Hello " + names)
    }
  }

  def say_bye {
    names match {
      case null => println("...")
      case listOfNames: List[String] => println("Goodbye " + listOfNames mkString(",") + ".  Come back soon!") 
      case _ => println("Goodbye " + names + ".  Come back soon!")
    }
  }
}

object MegaGreeter {
  def main(args: Array[String]) {
    val mg = new MegaGreeter
    mg.say_hi
    mg.say_bye

    // Change name to be "Zeke"
    mg.names = "Zeke"
    mg.say_hi
    mg.say_bye

    // Change the name to an array of names
    mg.names = List("Albert", "Brenda", "Charles",
            "Dave", "Englebert")
    mg.say_hi

    mg.say_bye

    // Change to nil
    mg.names = null
    mg.say_hi
    mg.say_bye
  }
}

Above is not really Scala idiomatic, but close to the original Ruby code especially how the class is created and used. Ruby still looks nice, but not as shiny as a few years ago. I am not here to say Scala is better than Ruby, but more of what is shiny before may not be as shiny today. Just like Java was shiny when I first time used it about 1996, it seems these days people see Java as the wart language. Scala will loose its shiny appeal in the next few years too.

I also been using the term "shiny", as its really about appeal. I still use Java and occasionally Perl, even if the are not shiny anymore. These older languages are still great in their own right. C is still cool these days.. I think.

Coin problem, how do you solve it?

2012-06-28T21:09:00.000+12:00

My son has this typical homework problem. If you have 10c, 20c and 1 dollar. How many ways can you make $2?

I am pretty sure there should be a combination formula for it, but I forgot. So I tried google but seems there is no formula

http://mathforum.org/library/drmath/view/57913.html

Is there really no formula?

Anyway so he started to make a table of combination. I told him I better start to see if I can code it, maybe it would help him to verify if the table of combination is correct. I came up w/ this. I hope its right otherwise his table of combination is wrong and my code is wrong.

val twoDollars = 200

val coinsCombo = for ( oneDollar <- 0 to (twoDollars/100);
 twentyCents <- 0 to (twoDollars/20);
 tenCents <- 0 to (twoDollars/10);
 if (oneDollar * 100 + twentyCents * 20 + tenCents * 10 == twoDollars) 
) yield (oneDollar, twentyCents, tenCents)
 
coinsCombo foreach println

println(coinsCombo.size)

Explaining C++, Java and Scala to my son

2012-06-28T20:53:00.000+12:00

Last night my son was asking about computers again. I think the conversation came about, what language is on my screen. I told him its Java and Scala. I talked about what is assembly, C, C++ and Objective-C and how it relates to Scratch and Kojo.

He asked about why it was named as C++, then I showed him a Java typical loop which is based C where we increment a counter.

int c = 0;
while (c <= 10) {
 System.out.println(c);
 c++;
}

He asked how the loop will be done in Scala. I started w/ a for comprehension, as he is familiar w/ loops on Scratch and Kojo.

for (c <- 0 to 10) {
 println(c)
}

Then he asked me about the for, <-, etc.

I then changed the code into

0 to 10 foreach println

His reaction "that is so awesome it's like english!"

misconception about h2 in memory db

2012-06-03T22:38:00.000+12:00

Seems sometimes I have seen h2 url connection as "jdbc:h2:mem", which is different from "jdbc:h2:mem:". The former will create a persistent db in the current path db called mem, the later will create a in memory db. The official docs explains in in more detail h2 docs.

A good way to know if its in memory or not is just check your current path. If you have mem.h2.db and mem.trace.db on the file system, then you are not using the in memory db.

Most of the time though more than 1 connection is needed. The first reaction is to remove the extra ":", rather than looking at the docs. The correct fix will be to name the memory db such as "jdbc:h2:mem:foo". Or if you use JPA sometimes the abstraction is just to thick, and most developers forget how connections are managed. A connection is closed per test, in general this is the last connection which leads to new db across a test suite. So to keep the db alive through out the lifetime of the JVM just add ";DB_CLOSE_DELAY=-1"

Short comparison of Ember.js and GWT

2012-05-27T21:11:00.000+12:00

Its been a while since I posted anything here, really hard to make continuous post. Well try again for the n-th time.

I have been using Google Web Toolkit (GWT) for while, as this is what we use at work. Its pretty good and has lots of positives, however it also has it's own negatives.

Lets go with the positives first:

For some people that knows Java they don't have to learn JS to develop full featured web apps
Existing java tooling works on GWT projects. Re-factoring, IDE support, etc.
Performance of GWT is still the best among any JS frameworks
Pretty good documentation and examples

Now for the negatives:

Not learning JS, or some people will need to learn Java to develop JS code
GWT seems to be on its own eco system outside of the wider JS eco system
Sometimes hard to control the html, making iterative changes with a web designer significantly more harder. This is even using ui binder
REST/JSON still seems to be 2nd citizen in GWT. There is autobeans in GWT now, however still lots of plumbing to do or use 3rd party library.

Using GWT to architect a full blown web app is great. Using established patterns such as Model View Presenter (MVP), a cousin of the more popular Model View Controller (MVC) pattern. For the past few years there has been a lot of JS MVC frameworks coming out. A quick look of the Todo MVC project will give us a lot of different implementation. (The GWT implementation hasn't been pulled yet). One of the JS MVC framework that's been gathering a bit of attention is Ember.js.

I gave ember.js a try over the weekend, its been initially a bit frustrating. Like always when you learn something new, sometimes we just need to unlearn our own old learnings. Ember documentation is a bit confusing, as its formatted on how to use the different features. Some of the materials I have found to helpful in getting me running are:

http://emberjs.com/documentation/

http://www.adobe.com/devnet/html5/articles/flame-on-a-beginners-guide-to-emberjs.html

http://www.infoq.com/articles/emberjs

http://awardwinningfjords.com/2011/12/27/emberjs-collections.html

After things started to fall in place, ember.js seems to be pretty straight forward. Compared to GWT there is really significantly less abstractions. As ember.js really tries get you in the middle of JS, HTML and CSS. I am still unsure on how unit testing will be done, haven't look at ember data yet, etc. However with this initial code:

var App = Em.Application.create();

App.Plant = Ember.Object.extend({
 id: 0,
 name: null,
 description: null
});

App.PlantsView = Em.View.extend({
 plantsBinding: 'App.PlantsController.content'
});


App.PlantsController = Em.ArrayProxy.create({
 content: [],
 
 init: function() {
  var me = this;
  var url = 'http://localhost/plants';
  $.getJSON(url,function(data){
    me.set('content', []);
    $(data.plants).each(function(index,value){
        var plant = App.Plant.create({
            id: value.id,
            name: value.name,
            description: value.description,
        });
        me.pushObject(plant);
    });
  });
 }
 
});

As you can see its really straight forward to get data from a rest/json server. I have an equivalent GWT project, but its too big to post here. However the equivalent GWT functionality would include. A model class, a ui binder file, an entry point class, a presenter interface, a view interface, a presenter implementation, a view implementation, http get code, etc.

This doesn't mean longer code is worse code, I am not in the camp of Java is bad too much typing. I still use Java, although less these days as Scala has pretty much filled the space. Even with the above code, one can see JS short coming of not having name spaces and no real support for OOP. However one can see also there is a lot less boiler plate and more natural integration with JS and HTML. When I mean less boiler, I do not mean about Java's verbose code but the bindings are straight forward. More natural integration, I just used jQuery's getJSON function straight out of the box and handlebars' template inside html. GWT has JSNI to call jQuery, but that is less natural and not used often.

Ember.js seems to be promising for organizing web apps. Then coupled with other mature JS frameworks like jQuery, I think it may make GWT a bit heavy for some use cases. I am still thinking of looking at Scala+GWT, aside from getting to use Scala to do JS I don't see a lot of difference from normal GWT.

Verify TRIM support on Linux

2011-09-18T16:54:00.000+12:00

Wasted my time today puzzling why the trim support of my ssd does not work, or I thought it wasn't but was working alright. When you google "linux trim verify" the link below and most people link to the site below. Apparently the tests is not fully correct. Most of the time it works for others, but not me. Maybe it has to do that I formatted my ext4 w/ -E stripe-width=128
Anyway this is a better test I found, but I can't seem to see the link anymore. Using my bash history for reference.

dd if=/dev/urandom of=tmpfile bs=1M count=10 && sync
hdparm --fibmap tmpfile
hdparm --read-sector [address between begin_LBA and end_LBA of previous command] # expecting random numbers here
rm tmpfile && sync && sleep 120
hdparm --read-sector [address between begin_LBA and end_LBA of previous command] # expecting zeroes

The real key is the sector address is somewhere in between and NOT the start sector, as its possible the trim command will not set things to zeroes if files overlap. As it had happened to me 9 out of 10 tries using the test below I get random numbers still. The test above I get zeroes consistently.

Manual setup of UEFI, GPT and GRUB2

2011-09-18T11:03:00.001+12:00

I recently got a Crucial m4. I then have to transfer my existing HDD on it. Its easier to do a clean install of Oneiric and it would pretty much do UEFI + GPT + GRUB2 for you. However if you want to manually transfer everything I did the following steps:

Boot on Oneiric live CD or another boot this that will boot in UEFI mode. Its important that boot is on UEFI mode and not BIOS mode
Go to a shell and install gdisk as we want to partition the SSD w/ GPT and not MBR. fdisk only supports MBR
```
apt-get install gdisk
```
Partition a EFI system partition. This would hold grub2 files later and other boot loaders if needed. I partitioned mine on sda1 as type EF00 (EFI System) w/ the size of 200mb. Yes a bit bigger than what is needed however most people recommend 200mb as some boot loaders needs a bigger space.
Format the partitions. The EFI System partition is formatted as vfat, as per EFI spec.
```
mkfs.vat /dev/sda1
mkswap /dev/sda2
mkfs.ext4 -E stripe-width=128 /dev/sda3
mkfs.ext4 -E stripe-width=128 /dev/sda4
```
I put in a stripe width of 128 k as there are some recommendation this is optimal for SSD. However test suggest that your mileage may vary.

Mount and create the dirs on EFI system partition

mkdir /boot/efi
mount /dev/sda1 /boot/efi
mkdir -p /boot/efi/efi

Install grub efi
```
apt-get install grub-efi-amd64
```

Setup grub on the EFI system partition

modprobe dm-mod
grub-install --boot-directory=/boot/efi/efi --bootloader-id=GRUB2 --no-floppy --recheck
cp /usr/share/grub/unicode.pf2 /boot/efi/efi/grub/
cp /boot/grub/grub.cfg /boot/efi/efi/grub/grub.cfg

I copied my old grub.cfg and update the UUID to point to the new SSD

Setup the EFI boot entry

modprobe efivars
efibootmgr --create --gpt --disk /dev/sda --part 1 --write-signature --label "GRUB2" --loader "\\EFI\\grub\\grub.efi"

GRUB2 is the entry that would appear on the EFI bootloader.

The following resource helped me a lot

https://wiki.archlinux.org/index.php/GRUB2#UEFI_systems

https://help.ubuntu.com/community/UEFIBooting#Install_GRUB2_in_.28U.29EFI_systems

I am still working out on the graphics output, This would only give you a text based grub.

HP 6910p 3G on linux

2011-01-08T00:54:00.003+13:00

I got the 3G hs2300 on the 6910p running before, but it was a long time ago. I would need internet access again on the road. I detached the battery and put in the sim card to test. It seems modem can't be detected. Doesn't appear on lsusb, not much clue on dmesg, I verified that its turned on bios, started to look around forums, tried various modprobe, was going to start using usb-modeswitch.

I then decided to reboot to Windows after several years of not going there. HP wireless assistant tells that its disabled as that the gsm sim is accessible and suggest to close or put the battery back. I put the battery back, HP wireless assistant changes status to still disabled but now suggest to fix via Device Manager. No luck, Device Manager can't find drivers, etc. So did not want to spend it running on Windows and maybe putting the battery back is enough to get it running on Linux again.

Reboot to linux, network manager picks it up. Nothing to setup aside from APN, etc. No driver install, etc. Just put the battery back. Hopefully this post saves someone a few hours diagnosing the problem. Just put the battery back and linux should see the hs2300 3G modem.

More on Scala

2010-08-31T22:54:00.005+12:00

Get Started on Debian/Ubuntu

Install scala, this would install version 2.7.7 though, 2.8.0 has just been out recently


apt-get install scala

Run the scala shell


scala

(optional) Quick upgrade to scala 2.8.0, install scala as per above and just copy the newer jars
Download scala from http://www.scala-lang.org/downloads and extract the tarball


tar xzf scala-2.8.0.final.tgz
cd scala-2.8.0.final/lib
cp scala-compiler.jar scala-library.jar scala-dbc.jar /usr/share/java

Get Started on Eclipse

Get the eclipse scala plugin http://www.scala-ide.org/ this would include the scala jar, compiler, console, etc.
When you have the plugin the following options are available

create a new scala project

right click on existing java project and add scala nature and you can now start coding both java and scala together

run the scala console inside eclipse

Reference and Links

Below are some useful reference

Scala Tutorial - useful w/ Java Background

Scala by Example - a little long, more like a scala cookbook

Programming Scala

First Steps to Scala - a bit old but still useful

Scala Idioms, Step 1, Lists and Maps - a bit old but quick way to learn about lists. Tuples are using old syntax of {x, y} which is now changed to (x, y)

Who is using Scala

Twitter

Foursquare

Sony, Siemens, etc.

Frameworks and OSS Projects

Lift

twitter

Scalaz

specs

esme

squeryl

scalatra

Looking at Scala again

2010-08-18T20:02:00.005+12:00

I have been look at scala and lift (web framework built on scala), on and off about a year now. I have revisited it again for the past few weeks. Scala as a language seems to be promising. For me it adds something new to the main stream languages today, like pattern matching (not regexp), functional programming, actors library. There are some languages that have these properties but I think scala has got some transitional properties giving some balance. Using scala you get to access java libraries natively, despite its terse syntax it is still a static language, this would mean tool developers will have an easier.

Scala
Lift

I have also been re-using emacs again. Some interesting scala emacs some stuff.

Scala emacs tools

Low tech stuff

2010-07-16T17:48:00.003+12:00

I have started on computers when its wasn't hip yet. When I was a kid, I toyed around a PC XT on green monochrome monitor. Then on to doing BASIC, then to over clocking on a Pentium when Asus brought out the first overclock board. Buying a linux book to get a slackware CD as downloading over a 2400bps modem is very slow. Time has passed so fast.

Lately the latest and greatest tech stuff hasn't been appealing for me. I do get touch the nice smart phones at work. Although new tech stuff isn't as appealing as before. Not sure why, maybe just too many tech stuff going around these days.

Back in the 80s there was something cool, which wasn't computers. I am talking about RC. Remote Control cars, me and my son have a few them.

These are low tech stuff, but very interesting for me. Its one of the interesting things to me as kid back then, aside from playing space wars on a PC XT. This appeals for me especially now as my son is able to build and play with me right now.

LXC on Ubuntu 10.04 Lucid Lynx

2010-07-16T16:22:00.007+12:00

If you are like me who doesn't have a lot of time anymore, at times trying new stuff is a lot harder. About a year ago I used kvm, which is great and easy enough to get up and running. I have used it since then however Kvm is a bit too much for my needs as its a full paravirt. Container based virtualization like vserver and openvz seems to be more challenging to get running on a laptop.

Fast forward today, it seems LXC Linux Containers (http://lxc.sourceforge.net) has now made some strides. Its now part of the main kernel, most modern distro should have like. Here is a quick guide on how to get lxc up and running on Ubuntu Lucid.

Below is to setup a debian lenny guest, that uses virbr0 and has dhcp. Do the following as root:

- install libvirt as its easier to do networking on it. No need to setup your own bridge, ipchains and nat. libvirt default qemu network should create a virbr0 interface.


apt-get install libvirt-bin

I have installed this prior for kvm. What we want is virbr0 is up and running. You check this by ifconfig. Try to start it manually on /etc/init.d/libvirt-bin

- install lxc


apt-get install lxc debootstrap

- create the capabilities dir and mount it


mkdir /cgroup

add to /etc/fstab
none /cgroup cgroup defaults 0 0

mount /cgroup

- get and edit the lxc-debian script from /usr/share/doc/lxc/examples/lxc-debian.gz (gunzip it somewhere and apply correct permissions)

Edit and add the following lxc parameters on copy_configuration() function before EOF


# networking
lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = virbr0
lxc.network.name = eth0
lxc.network.mtu = 1500
EOF

What this does is use the host virbr0 which is already NATed. This would appear as eth0 on the guest container.

You may need to edit increase the tty allowed, I was getting init warning on my syslog respawning. What I did was to edit my guest inittab to reduce the tty.


lxc.tty = 4 to lxc.tty = 6

- create your lxc dir. In my case the name of my container is "altair". Change it as you fit.


mkdir /home/lxc/altair
lxc-debian -p /home/lxc/altair create

This would start downloading debian lenny packages and create the root file system on /home/lxc/altair/rootfs.

- create the container


lxc-create -n altair -f /home/lxc/altair/config

- run the container


lxc-start -n altair

the above runs it on the foreground, once you have setup everything then you can run it as a deamon

lxc-start -n altair -d

Once you are inside the container, things that I did was
- set the hostname
- fix /etc/hosts
- add your favorite repo on /etc/apt/sources.list
- add X forwarding on ssh and install xauth package
- install rsyslog
- maybe edit your hosts /etc/hosts and add the IP address of the container.

Some useful links:

http://lxc.teegra.net/
http://blog.bodhizazen.net/linux/lxc-configure-ubuntu-lucid-containers/
http://nigel.mcnie.name/blog/a-five-minute-guide-to-linux-containers-for-debian
http://en.gentoo-wiki.com/wiki/LXC

HP 6910p, Acer 4315, HP dv6000 on Ubuntu 10.04 / Lucid Lynx

2010-07-16T16:05:00.005+12:00

Its been a while since I posted on this blog. Been very busy and had a few months not really keen about computers, more on that later. Anyway for the past few weeks I have installed Lucid on my aging laptops. So far Lucid has been pretty good. Everything runs right out of the box, I needed to install restricted wireless drivers for the Acer 4315 and HP dv6000. Very easy now, as you can do this on GUI. Gone are the days of downloading tars balls, patching kernels, compile and create kernel images.

There has been some minor issues. The Acer 4315 after resume has the wireless disabled sometimes. The volume is now better for Acer 4315. At times after resume the screen brightness is set to lowest, doesn't seem to appear lately.

For the 6910p xrandr is now able to rotate the screen. So at work my 2nd dvi monitor is vertically oriented. Great when doing code. My xrandr script has something like this.


xrandr --output DVI-0 --auto --rotate left --right-of LVDS --crtc 1

What I really liked about upgrading to Lucid is it seems LXC (Linux Containers) seems to be good enough now. I have stayed away from vserver and openvz, as I didn't have much time patching the kernel, then patching again all hardware to work (e.g. wireless) and suspend to work. Will have another post on how to get LXC running on Lucid pretty fast and hassle free.

Intrepid Ibex and virtualization

2008-12-26T22:53:00.005+13:00

I always wanted to do virtualization on my development workstation. There are some software that doesn't get along with one another, PHP5 and 4, apache 1 and 2. The list goes on. I also wanted the fact that I can upgrade my desktop w/o fearing to break things like Oracle libraries suddenly breaks because my distro decided to change libc.

It was a bit hard last year to make it work and let alone all the hardware of 6910p to work. I tried to use vserver and kvm, it was too hard to make a custom kernel to make everything work. I didn't try Xen as its an overkill for my needs, vserver is just fine for my needs. Also I think due to Xen design and objective it simply will not support suspend and resume on a laptop. vserver isn't even really a virtualization more like jail or chroot. This time I am trying again as Intrepid server comes with kvm as its virtualization choice. When I tried kvm last year it was the best candidate for me, however whenever I forget to stop a guest machine then I suspend the laptop I will get a hard lock. This time I am trying kvm which part of Ubuntu Interpid server edition, I am running Intrepid desktop and all I had to was to install the following packages.


apt-get install ubuntu-virt-server
apt-get install kvm libvirt-bin

I was too lazy to do things by hand, I gave the gui a shot. It was pleasantly surprising easy to install and run.


apt-get install virt-manager virt-viewer

It works! its not VMware easy but it close enough. Good enough for me that it does not get in the way and I can start putting my different projects in their own virtual space. I can even suspend and resume the laptop even if I forget the virtual guest machines are still running. Now I am shifting my projects that has similar virtual machines, like java-devel, rails-devel, etc. I am using Ubuntu JeOS as my guest OS, which is pretty good.

Acer Aspire 4315 on Ubuntu 8.10 / Intrepid Ibex

2008-12-26T22:39:00.004+13:00

I did an upgrade for the Acer 4315 from Hardy to Intrepid. There where a couple of issues, its similar to Hardy that I had to install the madwifi-ng driver for the Atheros wireless card to run. Its a bit easier now as they are now included on the backports.

sudo apt-get install linux-backports-modules-intrepid

Add ath5k on /etc/modules, reboot.

Then you need to switch the drivers on System->Administration->Hardware Drivers. Deactive the current default driver (Atheros 802.11 wireless LAN cards) and activate the 5xxx series of Atheros 802.11 wireless LAN cards.

I also encountered a new problem in Skype. It seems my Logitech S 5500 mic is very choppy, the mic is connected via USB. I didn't have time to fix it, so I just activated the mic of the laptop which works with Intrepid. This is likely a software problem, as the S 5500 works fine with the HP 6910p on Intrepid.

HP 6910p on Ubuntu 8.10 / Intrepid Ibex

2008-12-26T22:28:00.004+13:00

My HP 6910p is still running after 1 year. Hardware is still fine, I did a clean install of Intrepid a few days ago. So far its alright, the only problem I encountered was with wireless. Kinda weird that Hardy worked just fine, however it is a known issue and is clearly stated on Intrepid release notes. I had to add backports and then install the backported modules.

sudo apt-get install linux-backports-modules-intrepid

Since I also liked the radeonhd, works great with the HP docking station. I also installed it.

apt-get install xserver-xorg-video-radeonhd

Aside from that everything is still alright. I also noticed that suspend and resume works faster. The harddisk aggressive power management seems to have been taken cared of with Intrepid. I will be observing the load cycle times for the next few days.

Acer support and cashback (part 2)

2008-09-21T00:07:00.003+12:00

Now here is my cashback experience from Acer.

Jul 21 - Posted the required form, box cut out of the snid and invoice
checking the cashback status from time to time at Acer cashback website. Has always been on status where the documents hasn't been received yet.
Sep 8 - I noticed my status says "declined due to documents were not received by the due date". I emailed the cashback email address asking them how can this happen, and I asked them to give me some good explanation why on earth a mail from New Zealand to Australia will take 5-7 weeks to arrive.
Sep 9 - I noticed my status says "processing, check will be issued on ... November *something*"
Sep 16 - I got an email from Acer cashback telling me that they never recieved my documents. They are asking me to email or fax copies of the form, snid and invoice. I emailed them the digital copies of it, except for the box cut out of the snid. Its impossible for me to produce one as it was sent in the mail, I just shot a photo of the my snid on the bottom of the laptop.
Sep 17 - I got mail from Acer, its the $99 check. ?!? Are these guys confused of my status or what? Or did suddenly their cashback turnaround processing time is within 12 hours?

Acer cashback is not that bad if you only look into what happened on the start and end. I got the $99 cashback in 1.5 months, I was expecting it to be longer than that. However given that they are certainly confused or just radomly picking cashback status, their cashback is really poor. Oh yeah before getting the cashback form you will be bombarded with extended warranty option.

For those who go into Acer cashback process here are the following things that might help you.

scan the snid box cut out. Expect the worst that the mail will get lost, most likely somewhere in the cashback dept of Acer.
declined doesn't mean anything. They are just actually confused with your status, or probably trying to see if you the type of person that would just accept a decline status.
push for your cashback

Acer support and cashback (part 1)

2008-09-19T23:25:00.004+12:00

I would like to give out my long about my personal experience with Acer support and cashback.

Acer support:
Here is my long support story, which all started with a dvd combo drive going wrong.

Aug 3 - dvd combo drive started not to read dvd discs. After a few retry, ejects, etc. there is no more power on the drive.
Aug 4 - Called up Acer. Call center tech tries to go by the book, tells me reinstall driver, etc. I politely explained the problem further and told him that I am computer literate. Call center tech goes to the next step and files a case number, tells me that someone will call me regarding the repair. Told me that I don't need to bring in the laptop anywhere. I thought wow this is great, I bought a cheap laptop and I don't have to return it to base for repair. I knew something was a miss, but gave him the benefit of the doubt.
Aug 7 - I called Acer again since nobody has called me up. Yeah I know it was too good to be true. This call center tech told me that I should bring my laptop to Datacom which is their Wellington repair contractor.
Aug 12 - I brought the laptop to Datacom. I also left the power adapter as advised by Datacom (this event will trigger another sub-story).
Aug 19 - Called up Acer call center to ask what's the status of the repair and why its taking more than the 5 days turnaround time. Call center tech puts me on hold and comes back to me tell me that Datacom is ordering another dvd combo drive as the first replacement was also defective.
Aug 22 - Pickup of laptop after the 2nd replacement drive was deemed to be ok. I noticed the power adapter was different, but did not make a fuss about it. Laptop was also not cleaned up and has some minor new scratches (nothing to really fuss about).
Aug 22 - Got home to test the unit. I realized the adapter that Datacom returned to me was faulty (and older too), its wire was loose. The adapter was charging and discharging the laptop depending on the position and if the wire gets nudged.
Aug 22 - Called up Acer telling them about the power adapter issue and demanded to get it replaced. Call center tech places an order for an adapter to be shipped to me.
Aug 27 - New adapter has arrived. The dvd combo drive worked initially. After a while failed to read the dvd drives, can read some cdrom drives. Drive physically works, but has lots of crc errors and is unable to read the dvd discs most of the time.
Aug 27 - Called up Acer about the problem. Acer call center tech apologizes and opens a new case. Acer also arranged for my laptop to be picked up. They also told me not include the batteries and power adapter for the repair. Not including accessories is what I would have expected (SOP I have experienced with other repairs), not what Datacom did which caused a new problem regarding the power adapter.
Aug 29 - Courier arrived and picked up the laptop. After a few days some message exchanges on the Acer support website to get the status of the repair.
Sep 1 - The adapter also came with a notice I need to return the defective power adapter in 10 days or else they will invoice me $50. Called up Acer, call center tech tells that yes I need to post back the defective courier and gave the address. He also tells me that I need to ship back at my expense, despite my protest. I posted this protest on the support website, that I should not shoulder the expense to ship back as it was not my fault that Datacom replaced my power adapter with a defective unit.
Sep 2 - Acer call center tech calls me up that they are sorry and will arranged a courier pickup for the power adapter. My support case on the support website was also updated with this information.
Sep 5 - Acer call center tech calls me up telling me that there was a mixup. The notice to return the defective adapter should have been given. They will not pickup the defective adapter anymore and I can dispose of it.
Sep 8 - Laptop finally arrives. The dvd combo drive was also upgraded to a Lite-on dvd writer. I am not sure if the upgrade was delibrate or a honest mistake on Acer's part.

In short, it was long support case just to get the dvd combo drive sorted. Acer's Wellington local contractor Datacom is poor. They should have a stock of a common part like a dvd combo drive, should not have got the power adapter and other accessories when turning in a laptop for repair, should clean and take extra careful of the laptop while on repair. Acer's call center tech are confused about things, they are not consistent. I found the support website to be a better way of contact, you get slower reply times though. Demand the support you deserve in a polite manner after all the other person the other end is just on his/her day job. Acer did eventually stepped up and sorted things out. Acer support in Wellington, NZ is poor primarily because of their local repair contractor Datacom.

Wow this support story is very long, I need to sleep. I will post up my cashback experience hopefully tomorrow which is equally hilarous.

Acer Aspire 4315 short review and Ubuntu 8.04 (Hardy) install

2008-07-23T00:00:00.006+12:00

We got an Acer Aspire 4315 since we needed an extra laptop around. As both the 6910p and dv6000 is being used normally. We wanted something cheap for e-mail, skype, browsing, watching dvd and document editing. The Acer Aspire 4315 seems to fit the bill especially the price.

Specifications

Processor: Celeron M 540 1.86GHz, 1MB Cache, 533MHz FSB, 64-bit capable
RAM: 512MB DDR2-667(1 x 512MB)
HDD: 80GB 5400rpm SATA
Display: 14.1" WXGA CrystalBrite widescreen (1280 x 800)
Optical: DVD+CDRW Combo
Wireless: Yes 802.11b⁄g
Graphics: Intel Graphics Media Accelerator X3100 up to 358MB
Firewire⁄S-video⁄FIR: No⁄Yes⁄No
VGA Out: Yes
USB Ports: x 3
Ethernet 10⁄100: Yes
Express Card slot: Yes
Battery: 6 cell

Cost

Acer Aspire 4315 = $598
512mb upgrade = $30
512mb clearance and bundle = -$30
we got the display model as its the last in store = -$30
acer cashback promo = -$99
Total cost = $469 NZD ~ $356 USD

Short Review

What have we got for $470 bucks? A pretty decent laptop if you ask me. Build quality is pretty good. Keyboard is pretty sturdy and no flex, in fact its probably better than our HP dv6000. The hinges is firm and solid, not as good as the HP 6910p but good enough. Performance wise its just as good as the HP 6910p on most everyday tasks, and what we intended to use it for (e-mail, skype, browsing, watching dvd and document editing).

Minor problems as other owners of Acer 4315 has stated:
- touchpad is very near the keyboard, I tend to touch it accidentally while typing.
- speaker sound is a bit low, however quality is pretty good. Maybe better sounding than the 6910p. It does not sound like a tin can, just not as loud as you would expect.

Ubuntu 8.04 (Hardy)

The Acer Aspire 4315 comes with Ubuntu 7.10 (Gutsy), which is great and no need to pay Windows Vista that I don't use. I immediately installed 8.04 Hardy on it, I used the alternative CD since that is what I downloaded. I did some post install steps which came from this guide.

Status

Ethernet	works
Wireless	works, needs post install steps
Video	works
Suspend and Hibernate	works, suspend works with updated hardy kernel
Splash screen and virtual terminals	works
Harddisk Power management	needs post install steps
Audio and Mic	works, needs post install steps for proper resume
Screen brightness	works

Post Install Steps

Wireless

The atheros card will only work with madwifi-ng, stated on this guide


sudo apt-get update && sudo apt-get install build-essential
wget -c http://snapshots.madwifi.org/special/madwifi-ng-r3366+ar5007.tar.gz
tar xvf madwifi-ng-r3366+ar5007.tar.gz
cd madwifi-ng-r3366+ar5007
sudo make install
sudo modprobe ath_pci
sudo modprobe wlan_scan_sta

Audio and Mic

After resuming it doesn't have audio and mic. There are some suggestions to do "sudo /sbin/alsa force-reload" which works. I find it annoying as the volume control applet will complain and needs to be reloaded. What I did was to edit /etc/modprobe.d/alsa-base and added this at the end of the file


# properly detect the sound again after resume
options snd-hda-intel model=acer

Take note after reboot, volume control will be different. Re-adjust accordingly.

The mic does work, but its very hard to fine tune the proper level. Too low and I hardly hear myself, too loud and it shuts itself or there are lots of crackle. I ended up just plugging in a front external mic.

Harddisk Power Management

Just like the HP 6910p, the Acer Aspire 4315 came with a Hitachi disk (Hitachi HTS542580K9SA00). This also suffers from the over aggressive power management. I used my old guide, but the script will not work as in Gutsy its placed on "/etc/acpi/resume.d" which is not sourced anymore, I placed the script on "/etc/pm/sleep.d" on Hardy. There is a launchpad bug filed on this, apparently Ubuntu changed things a bit.

Summary

The Acer Aspire 4315 is a great laptop, cost 1/7th of the HP 6910p. I can surely say that the value is more than 1/7th of the HP 6910p. Comes with Ubuntu 7.10 pre-installed, installing Ubuntu 8.04 Hardy is also straight forward with a few post install steps. Now time to wait for that cash back check to arrive.

HP 6910p on Ubuntu 8.04 / Hardy Heron

2008-07-22T23:09:00.014+12:00

I have upgraded from Ubuntu 7.10 (Gutsy) to 8.04 (Hardy). This is not a clean install however I made some effort to remove any post install steps that was done previously with my 7.10 Gutsy guide.

HP 6910p specification:

CPU: Intel Core 2 Duo T7700 (2.4Ghz)
Display: 14.1" WXGA+ 1440x900
GPU: AMD/ATI Radeon X2300
RAM: 2GB (2x1GB)
Harddisk: 120GB 7200rpm Hitachi 7k200 Travelstar
Optical Drive: MultiBay II DVD SM DL
Wireless: Intel Pro/Wireless 4965 a/b/g/n, Bluetooth, Infrared
Ports/slots: 3xUSB 2.0; MultiBay II; Intel 82566MM 10/100/1000 Lan; Modem; S-Video out; VGA out; Firewire; Audio in; Audio out; internal microphone; SD/MMC card reader; Smart Card Reader; Type I/II PC Card Reader; SIM card slot; Docking connector; Second battery connector.
Other: Finger print reader, Touch stick with 2 buttons, Touch pad with 2 buttons, Volume up – down, Volume mute, Presentation, Wireless, HP Info Centre touch sensitive buttons.

Status:

Ethernet	works
Wireless	works
Video	works, using radeonhd
Suspend and Hibernate	works
Splash screen and virtual terminals	works
Harddisk Power management	needs post install steps
Fingerprint reader	works
Audio and Mic	works
Bluetooth	works
Screen brightness	does not work inside X, but light sensor works
Card reader	detected with intrepid kernel, some issues see comments below
Docking station	works including dvi

Post Install Steps:

Harddisk Power management

It seems this isn't resolved yet. I brought back my changes for the hard disk not to park its head excessively. This only affects a few select 6910p using a particular model of harddisk. This is not a 6910p issue but more of harddisk issue.

Summary:

The upgrade to 8.04 Hardy removed the post install steps that was needed for 7.10 Gutsy, which is what I expected. Since mine is not a clean install and I am unlikely to do a clean install due to the lack of time, anyone has a story from a clean install?

Quick update

2008-07-18T17:45:00.004+12:00

Well I am still alive, been very busy and had some series of unfortunate of health problems. Today I had some spare time, I upgraded to Hardy Heron using the update manager. So far everything is still alright. I haven't seen any needed customization yet, will check if the hard disk park issue is fixed. Suspend, works. wifi, works.

This is an upgrade from Gutsy and not a clean install. Things that still don't work is the brightness function key. I will try to check the other stuff over the coming days and probably list in detail.

I just need to bring back my customization, oracle, tomcat, etc.