linux instead

To convert most video files into DVD compatible mpg files, mencoder is a good option.

The following will convert to PAL widescreen format.

mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -vf scale=720:576,harddup -srate 48000 -af lavcresample=48000 -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=9800:vbitrate=5000:keyint=15:aspect=16/9:acodec=ac3:abitrate=192 -ofps 25 -o "OUTPUT.mpg" "INPUT.avi"

I decided it was time to change my mobile phone. Being a Linux nerd I decided to opt for an Android based phone.
There are quite a number to choose from. The HTC Hero being the most popular, but at the time this would have cost me £360 of my hard earned cash.
T-Mobile have released an ‘own brand’ phone, the pulse, manufactured by Huawei. At the time of writing you can get one for under £150.

The pulses spec is very similar to that of the hero, but with slightly less memory, leaving just 60mb left to install new apps into. For reasons best known to google, android apps cannot be installed onto the SD card which is a real shame not least for the apps market in general. (continue reading…)

I’ve just installed the 64bit version of Ubuntu 9.04 onto my main desktop PC. Everything was going well until I wanted to print a document.
No, my printer was correctly detected and when I clicked ‘print’ the printer burst into life as expected. But after printing about half of the first page the printer just stopped. My printer is a HP Deskjet F2100 series (F2180 to be precise).

I tried everything, google didn’t throw up anything useful, I installed later HP drivers but noting fixed it.

After a lot of head scratching ad experimenting I did notice something odd. The USB device as owned by a user I did not have permissions for. I wasn’t expecting this to be the cause of the problem because if it was due to permissions then surely the printer would not print at all?!?

I was wrong, and adding myself to the group that owned the USB device has fixed it. As this seemed quite off the wall I thought I’d share…
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For distros that don’t support XEN compatible installers the easiest way to create a PV (ParaVirtual) DOMU is to install as a HVM (see my other article entry for this) ad then once installed, convert it to a PV DOMU.

There are several reasons why you might want to go with PV instead of HVM. The main two that spring to mind are PV’s offer better performance/lower overhead and PV DOMU’s allow PCI passthrough. Although apparently XEN 3.4 can now do PCI passthrough with HVM, as long as you have an Intel chip with vt-d.

This article will start off where my previous “Installing a XEN hvm DOMU” left off…
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For this to work your CPU and motherboard needs to support vt (intel) or amd-v. You can check this by looking at the flags in /proc/cpuinfo. Your looking for either vmx or svm on the flags line.

If you’re doing this from your DOM0 then these flags may not actually show up. Instead type xm info and look for ‘hvm’ on the virt_caps line.

For my hvm install, i’ll be installing Ubuntu 9.04 Desktop Linux.
I have copied the live CD ISO onto my XEN DOM0 and will be installing directly from the iso rather than burning the CD. I have also created a 10GB LVM logical volume to act as the disk for my new DOMU.
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This is a quick guide to setting up a Linux software RAID mirror (aka RAID 1).

There are a couple of toolsets for managing raid on Linux, raidtools and mdadm. This guide will use mdadm because imho it has better commands and features for monitoring.

Right, first you’ll need a couple of disk partitions of about the same size. These should be on separate disks or you’ll be defeating the point of raid mirroring
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Sometimes I find it useful to switch to hex mode when editing a file in vi. The command for switching is not very obvious so thought I’d share…

So, open a file in vi as usual, hit escape and type:
:%!xxd to switch into hex mode

And when your done hit escape again and type:
:%!xxd -r to exit from hex mode.

If you’ve followed my guide to installing xen from source then you might now be wondering how to create your first VM.
This guide will show you how to manually create and install a VM (known as a DOMU instance in Xen) without any additional tools such as virt-manager, virt-install or virsh. These tools can help the novice, but are quite limiting when it comes to the advance features of xen.

For this example I’ll be installing CentOS5, but this should work for any red-hat based distro (please note there is a bug in fedora10 that stops it booting under xen). This example also uses the paravirtual kernel so it will work even if your CPU does not support AMD-V or intel-VT.

Right, down to business. The first thing we need to do is create a file to user as the hard disk for the DOMU. There are other options for providing hard disks to a DOMU, and I’ll cover some of them in a later guide but for this install I’ll be using a file.

The command below will create an 8GB file that will be used as an 8GB drive. The whole file will be written to disk in one go so may take a short while to complete.
dd if=/dev/zero of=/xenimages/test01/disk1.img oflag=direct bs=1M count=8192
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This is a quick and dirty guide to setting up an LVM based filesystem.

First create some disk partitions. In this example I’ve got two identical unformatted partitions on a couple of hard drives. These appear in /dev as sda4 and sdb4. Please note your partition number will most likely be different.
Also note that it’s easy to break your system with some of these commands. You have been warned, so don’t blame me if you wipe your system out!

First make the partitions available to LVM:
pvcreate /dev/sda4
Physical volume “/dev/sda4″ successfully created
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This is how I built my Xen server.

First install Debian 5.0 (Lenny). This should also work on 4 (Etch) too.

Everything is done on the command line as root.

To build Xen from source you’ll need as fair number of dependencies. The easiest way to install them is by using the apt-get install command as below:
apt-get install bcc bin86 gawk bridge-utils iproute libcurl3 libcurl4-openssl-dev bzip2 module-init-tools transfig tgif texinfo pciutils-dev mercurial build-essential make gcc libc6-dev zlib1g-dev python python-dev python-twisted libncurses5-dev patch libvncserver-dev libsdl-dev libjpeg62-dev

If you installed the 64bit version of Debian then you’ll also need gcc-multilib for the compile to work:
apt-get install gcc-multilib
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