This guide describes how to upgrade your XstreamTec HTPC appliance from XBMC to KODI or re-install the system, in case of system corruption.

XstreamTec does not appear to have an official website but I have contacted them via Amazon and they promptly replied with instructions.


  • An XstreamTec HTPC media player.
  • A Linux system with an SD card slot.
  • A Windows PC or VM (optional).
  • An empty SD card (4GB minimum).

Install the recovery firmware

  1. Download the android recovery sd card image (use Google Chrome or Chromium):!wExHTJgC!XPuoFyhF_S-roTEhsMhQ8BLrfH4R5tXhp2jwaLF_o1M

    • Convert the image to raw format:

      If you extract the downloaded file (MATRICOM_MX2_115_FULL_AUG_09_2013.rar) you will get the image file (MATRICOM_MX2_115_FULL_AUG_09_2013.imgc). Alas this file has a peculiar format (.imgc) which is some kind of compressed raw image. I couldn’t figure out how to convert this to a raw (suitable for dd) image on Linux. To convert this to raw you need a Windows only utility called HDDRawCopy. So you will need a Windows system (WINE does not work for this) and use HDDRawCopy to convert the .imgc file to Raw/dd format.

      If you do not have a Windows machine, you can download the image I converted already, in .bz2 format from here: MATRICOM_MX2_115_FULL_AUG_09_2013.dd.bz2. Just extract it like this to get the raw image:

    $ cd ~/Downloads
    $ bzip2 -d MATRICOM_MX2_115_FULL_AUG_09_2013.dd.bz2
    • Prepare the SD card:

      Make sure you don’t have any useful data on the SD card!

      First verify that the SD card is inserted:

      $ cat /proc/partitions 
      major minor  #blocks  name
        8        0  488386584 sda
        8        1     524288 sda1
        8        2     249856 sda2
        8        3  487610368 sda3
       11        0    1048575 sr0
      252        0  487608320 dm-0
      252        1  483524608 dm-1
      252        2    4067328 dm-2
      179        0    7761920 mmcblk0
      179        1      71680 mmcblk0p1
      179        2     124928 mmcblk0p2
      179        3    7559168 mmcblk0p3

      Unmount all partitions on the SD card:

      $ sudo umount /dev/mmcblk0p*

      Now use fdisk and delete all partitions from the SD card:

      $ sudo fdisk /dev/mmcblk0
    • Dump the image on the SD card:

      After preparing the SD card we need to dump the raw image on it:

       $ sudo dd if=MATRICOM_MX2_115_FULL_AUG_09_2013.dd of=/dev/mmcblk0

      Be very careful with dd! If you specify the wrong device on the of= parameter you may destroy useful data on other devices, even you main hard disk!

Boot the recovery image

Now we need to go though these steps to load the recovery image:

  1. Power off the XstreamTec appliance.

  2. Insert the SD card, in the SD slot of the XstreamTec.

  3. Press the reset button. This is somewhat tricky. The reset button is inside the AV port of the XstreamTec so you will need a toothpick to press it.

  4. Power on the appliance, while keeping the reset button pressed. The system will enter the recovery installation procedure. Release the reset button when the recovery starts.

  5. Follow the on-screen instructions to load the Android recovery image. Then reboot into android and see if it boots correctly.

Install the newer version of the Android system

Now we need to install a more recent version of Android on the XstreamTec.

  1. Download the newer Android firmware:

    $ cd ~/Downloads
    $ wget
  2. Prepare the SD card:

    • Insert the SD card in your PC and check if it is mounted:

      $ df -hT | grep mmc
      /dev/mmcblk0p1              vfat      3,7G  100M  3,6G   3% /media/user/0E99-207A
    • Delete all previous files from the SD card:

      $ cd /media/user/0E99-207A
      $ rm -fr * 

      Once again make sure you don’t have any data you need on the SD card.

  3. Load the firmware on the SD card.

    Unzip the contents of the downloaded zip file ( on the SD card:

    $ cd /media/user/0E99-207A
    $ unzip ~/Downloads/

Boot the new Android firmware

Go through these steps agaon to load the new Android firmware:

  1. Power off the XstreamTec appliance.

  2. Insert the SD card in the SD slot of the XstreamTec.

  3. Press the reset button. Repeat the toothpick procedure as previously.

  4. Power on the appliance while keeping the reset button pressed. The system will enter the new Android firmware installation procedure. Release the reset button when the recovery starts.

  5. Follow the on-screen instructions to load the new Android firmware. Then reboot into the new Android and see if it boots correctly.

One would be tempted to keep the Android system and use XBMC or install Kodi on it. This way you can have Android and XBMC/Kodi on your XstreamTec appliance. Alas the XBMC/Kodi experience for Android is not as good as the one on OpenELEC. Trust me, if you need the full Kodi experience you need to install OpenELEC.

Install OpenELEC on the XstreamTec HTPC media player

  1. Download the OpenELEC firmware:

    $ cd ~/Downloads
    $ wget
  2. Prepare the SD card:

    • Insert the SD card in your PC and check if it is mounted:

      $ df -hT | grep mmc
      /dev/mmcblk0p1              vfat      3,7G  100M  3,6G   3% /media/user/0E99-207A
    • Delete all previous files from the SD card:

      $ cd /media/user/0E99-207A
      $ rm -fr * 
  3. Load the OpenELEC firmware on the SD card.

    Unzip the contents of the downloaded zip file ( on the SD card:

    $ cd /media/user/0E99-207A
    $ unzip ~/Downloads/

Boot the OpenELEC firmware

Once again repeat these steps to load the OpenELEC firmware:

  1. Power off the XstreamTec appliance.

  2. Insert the SD card in the SD slot of the XstreamTec.

  3. Press the reset button. Repeat the toothpick procedure as previously.

  4. Power on the appliance while keeping the reset button pressed. The system will enter the OpenELEC installation procedure. Release the reset button when the recovery starts.

  5. Follow the on-screen instructions to load the OpenELEC firmware. Then reboot into your freshly installed system and see if it works properly.

Enjoy your Kodi experience!


This is a guide to setup a recent Ubuntu system on a Utilite ARM computer, to replace the official Ubuntu 12.04 OS.


  • You need to prepare a kernel with cgroups support.
  • An ARM bootable microSD or USB. You can use the official Ubuntu 12.04 Linux Utilite Image on the removable device.
  • Backup any data you have on the original system!


  1. Boot from microSD or USB.

  2. Update the system and install debootstrap:

    $ sudo apt-get update
    $ sudo apt-get install debootstrap
  3. Mount the SATA root filesystem on /mnt:

    $ sudo mount /dev/sda2 /mnt
  4. Clear the filesystem:

    Make sure you save any data you need, before doing this!.

    $ sudo rm -fr /mnt/*

Installation of an Ubuntu or Debian base system

  1. Use debootstrap to install the Ubuntu base system:

    $ sudo debootstrap --foreign --arch=armhf trusty /mnt

    You can use vivid instead of trusty if you are feeling adventurous.

    For a Debian system use this command instead:

    $ sudo debootstrap --foreign --arch armhf jessie /mnt

    You can use stretch or sid instead of jessie if you are feeling lucky.

  2. Chroot into the new system:

    $ sudo mount -o bind /dev /mnt/dev
    $ sudo mount -o bind /dev/pts /mnt/dev/pts
    $ sudo mount -t sysfs /sys /mnt/sys
    $ sudo mount -t proc /proc /mnt/proc
    $ sudo cp /proc/mounts /mnt/etc/mtab
    $ sudo chroot /mnt
  3. Second stage debootstrap:

    After you enter the chroot jail, we need to complete the second stage of the base setup:

    # /debootstrap/debootstrap --second-stage

Installing additional packages

  1. Setup the correct timezone:

    # dpkg-reconfigure tzdata
  2. Add repositories in /etc/apt/sources.list.

    • For Ubuntu:

      deb trusty main restricted universe multiverse
      deb trusty-security main restricted universe multiverse
      deb trusty-updates main restricted universe multiverse
      deb trusty-backports main restricted universe multiverse
      deb-src trusty main restricted universe multiverse
      deb-src trusty-security main restricted universe multiverse
      deb-src trusty-updates main restricted universe multiverse
      deb-src trusty-backports main restricted universe multiverse
    • For Debian:

      deb jessie main contrib non-free
      deb jessie-updates main contrib non-free
      deb jessie/updates main contrib non-free
      deb-src jessie main contrib non-free
      deb-src jessie-updates main contrib non-free
      deb-src jessie/updates main contrib non-free
    • Run update after adding the repositories:

      # apt-get update
  3. Install additional software.

    • We need to create a fake /sbin/initctl to prevent apt from breaking:

      # dpkg-divert --local --rename --add /sbin/initctl
      # ln -s /bin/true /sbin/initctl
    • Install the software you need:

      # apt-get -y install language-pack-en ssh isc-dhcp-client net-tools man lsof less
    • Remove the fake /sbin/initctl:

      # rm /sbin/initctl
      # dpkg-divert --local --rename --remove /sbin/initctl
  4. Setup users:

    # passwd root
    # useradd -m -s /bin/bash utilite
    # passwd utilite
    # usermod -a -G adm,cdrom,sudo,dip,plugdev utilite
  5. Setup a kernel:

    Now you need to deploy the kernel we prepare earlier and reboot.

Choose a role for your system

  1. After you reboot you may find that networking is not working. If you are in a dhcp enabled network run dhclient to get an IP address:

    # dhclient 
  2. Upgrade the system to the latest upgrades:

    # apt-get update
    # apt-get -y dist-upgrade
  3. Check the available roles

    • On Ubuntu you may want to install tasksel (already installed on Debian):

      # apt-get install tasksel
    • See the available roles on Ubuntu:

      # tasksel --list-tasks
      i server        Basic Ubuntu server
      i openssh-server        OpenSSH server
      u dns-server    DNS server
      u lamp-server   LAMP server
      u mail-server   Mail server
      u postgresql-server     PostgreSQL database
      u print-server  Print server
      u samba-server  Samba file server
      u tomcat-server Tomcat Java server
      u cloud-image   Ubuntu Cloud Image (instance)
      u virt-host     Virtual Machine host
      u ubuntustudio-graphics 2D/3D creation and editing suite
      u ubuntustudio-audio    Audio recording and editing suite
      u edubuntu-desktop-gnome        Edubuntu desktop
      u kubuntu-active        Kubuntu Active
      u kubuntu-desktop       Kubuntu desktop
      u kubuntu-full  Kubuntu full
      u ubuntustudio-font-meta        Large selection of font packages
      u lubuntu-desktop       Lubuntu Desktop
      u lubuntu-core  Lubuntu minimal installation
      u mythbuntu-frontend    Mythbuntu frontend
      u mythbuntu-backend-master      Mythbuntu master backend
      u mythbuntu-backend-slave       Mythbuntu slave backend
      u ubuntustudio-photography      Photograph touchup and editing suite
      u ubuntustudio-publishing       Publishing applications
      u ubuntu-gnome-desktop  Ubuntu GNOME desktop
      u ubuntu-desktop        Ubuntu desktop
      u ubuntu-usb    Ubuntu desktop USB
      u ubuntustudio-video    Video creation and editing suite
      u xubuntu-desktop       Xubuntu desktop
      u edubuntu-dvd-live     Edubuntu live DVD
      u kubuntu-active-live   Kubuntu Active Remix live CD
      u kubuntu-live  Kubuntu live CD
      u kubuntu-dvd-live      Kubuntu live DVD
      u lubuntu-live  Lubuntu live CD
      u ubuntu-gnome-live     Ubuntu GNOME live CD
      u ubuntustudio-dvd-live Ubuntu Studio live DVD
      u ubuntu-live   Ubuntu live CD
      u ubuntu-usb-live       Ubuntu live USB
      u xubuntu-live  Xubuntu live CD
      u manual        Manual package selection
    • See the available roles on debian:

      $ tasksel --list-tasks
      i desktop Debian desktop environment
      u gnome-desktop   GNOME
      u xfce-desktop    Xfce
      u kde-desktop KDE
      u cinnamon-desktop    Cinnamon
      u mate-desktop    MATE
      i lxde-desktop    LXDE
      u web-server  web server
      u print-server    print server
      u ssh-server  SSH server
      u laptop  laptop
  4. Choose a role.

    If you would like a Desktop system, I suggest you choose something light like lubuntu-desktop or lxde-desktop.

    • Installing Lubuntu (Ubuntu):

      # tasksel --task-packages lubuntu-desktop | xargs apt-get -y install

      I prefer this method rather than the TUI of tasksel, so as to have better overview and control of the process. Keep an eye on it every now and then, because it will ask you about keyboard-configuration and other questions. Select the default settings if you are unsure.

    • Installing LXDE Desktop (Debian):

      # apt-get install task-lxde-desktop network-manager

      For Desktop systems it may be a good idea to install network-manager as well.

    • Add the vivante GPU module on startup:

      # echo vivante >> /etc/modules

After you finish you can reboot your system and start playing.


The Utilite computer comes with an aging Ubuntu 12.04. If you try to upgrade it to to 14.04 or later, you will end up with a broken system because of their dependency, either fully or partially, on the systemd init system. The problem is that the stock kernel does not support cgroups which is a mandatory dependency for systemd. Type these commands on your Utilite, to verify the missing feature:

$ sudo mount /dev/sda1 /boot
$ /usr/src/linux-kernel/scripts/extract-ikconfig /boot/uImage-cm-fx6 | grep CGROUPS
# CONFIG_CGROUPS is not set

There is also another important feature: fhandle. A systemd Linux system without an fhandle enabled kernel, will fail to enable the swap space during boot.

Most modern distros, with a few notable exceptions, have switched to this new initialization system. So if we want to use a recent version of Ubuntu, Debian or most other distros, we need to recompile the kernel with cgroups support.


  • A standard x86-based PC with Linux installed (I use Ubuntu 15.04 at present). This is going to be our build station.
  • A Utilite ARM Computer. This is our target.

Prepare the cross-compile toolchain

The necessary packages are available on recent Ubuntu releases and Debian unstable.

First let’s install all necessary and optional packages on our build station:

$ sudo apt-get -y install build-essential gcc-arm-none-eabi gcc-arm-linux-gnueabi gcc-arm-linux-gnueabihf libncurses5 libncurses5-dev libncursesw5 libncursesw5-dev lzop git u-boot-tools pkg-config

Download the kernel sources

  1. You can download the sources from here:

    $ wget
  2. Then extract the tarball and change into the kernel source root:

    $ tar xvzf master.tar.gz
    $ cd linux-kernel-3.0-master/

Building the kernel

  1. Prepare the environment:

    $ export ARCH=arm
    $ export CROSS_COMPILE=arm-linux-gnueabihf-
  2. Prepare the configuration for utilite:

    $ make utilite_defconfig
    • Check if cgroups and fhandle are enabled:

      $ grep CGROUPS .config 
      # CONFIG_CGROUPS is not set
      $ grep FHANDLE .config 
      # CONFIG_FHANDLE is not set
    • Since cgroups and fhandle, are not enabled we need to enter menuconfig to enable it:

      $ make menuconfig

      Navigate to General Setup and go down to Control Group support. Press the space bar and you will see an asterisk ([*]). That means the Control Group support feature is enabled to be compiled in the kernel. Now do the same with the open by fhandle syscalls option. Press exit and Yes to save your new configuration.

    • Make sure cgroups and fhandle are now enabled:

      $ grep CGROUPS .config 
      $ grep FHANDLE .config

      Good. Let’s proceed with the build.

  3. Build the kernel and prepare a U-boot compatible image (uImage):

    $ make
    $ make uImage

    This will take some time depending on how powerful your build station is. Go for coffee, watch some movie, read a comic

Prepare the tarball

Now we need to package the kernel and modules together.

  1. Install the modules in the rootfs directory:

    $ mkdir -p rootfs/boot
    $ INSTALL_MOD_PATH=./rootfs make modules_install

    Ignore this error after make modules_install:

    make[1]: *** No rule to make target 'rootfs/lib/firmware/./', needed by 'rootfs/lib/firmware/ti_3410.fw'.  Stop.
    Makefile:1130: recipe for target '_modinst_post' failed
    make: *** [_modinst_post] Error 2
  2. Copy the image and prepare the tarball:

    $ cp arch/arm/boot/uImage rootfs/boot/uImage-cm-fx6
    $ cp arch/arm/boot/zImage rootfs/boot/zImage-cm-fx6
    $ cd rootfs
    $ tar cvzf ../linux-utilite-kernel-3.0.tar.gz .
    $ cd ..

Deploy the tarball

Now we are ready to deploy the kernel to the Utilite computer.

  1. Copy the kernel to the Utilite computer:

    $ scp linux-utilite-kernel-3.0.tar.gz utilite@utilite-desktop:
  2. Now connect to the Utilite and mount the boot partition:

    $ sudo mount /dev/sda1 /boot
  3. Backup the existing files and remove the old image and modules:

    $ tar cvzf linux-utilite-original-kernel.tar.gz /boot/ /lib/modules/3.0.35-cm-fx6-6.3/
    $ sudo rm /boot/uImage-cm-fx6 
    $ sudo rm -fr /lib/modules/3.0.35-cm-fx6-6.3

    If something goes wrong you can boot from a microSD or a USB drive and restore the original kernel.

  4. Deploy the kernel:

    Make sure the /boot directory is mounted on the /dev/sda1 filesystem before running the following command.

    $ sudo tar xvzf linux-utilite-kernel-3.0.tar.gz -C /
    $ sudo chown -R root:root /lib/modules/3.0.35-cm-fx6-6.4
    $ sudo depmod 3.0.35-cm-fx6-6.4

    The errors caused by tar are produced because FAT filesystem like /dev/sda1, do not support the ownership attribute. You can safely ignore them. chown is used to set the owneship of the modules to the root user, since the tarball was packaged under a normal user account and inherited its permissions.

You can now reboot the Utilite and see if everything works as expected. If not, you can boot with a microSD or a USB flash drive and restore the original kernel and modules.

After we have successfully prepared a cgroups enabled kernel, we can move on to setup a new Ubuntu or Debian system on the Utilite.


I have mentioned in an earlier post that I am an owner of a Utilite ARM computer. One of the issues I experienced with the default setup, is that there is no swap partition. That causes Firefox some memory hungry applications to perform badly.

Check for yourself, if swap is activated on your machine:

            total       used       free     shared    buffers     cached
Mem:       2006476     263752    1742724      20100      21428     107388
-/+ buffers/cache:     134936    1871540
Swap:            0          0          0

As you can see in the output, no swap space is used. So we are going to see how we can resize a linux ext2/ext3/ext4 partition to make space for a swap partition. We are then going to create a new swap partition and activate it on boot.


Checking the current setup

After you boot using a removable medium, you can follow this procedure to check the current setup:

$ sudo fdisk -l /dev/sda

Disk /dev/sda: 29.8 GiB, 32017047552 bytes, 62533296 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xa5161f73

Device     Boot  Start      End  Sectors  Size Id Type
/dev/sda1  *      2048   206847   204800  100M  c W95 FAT32 (LBA)
/dev/sda2       206848 62533295 62326448 29.7G 83 Linux
  • START_SECTOR = 206848
  • END_SECTOR = 62533295
  • TOTAL_SECTORS = 62326448

As you can see, the main root partition (sda2) has a size of 29.7GB. We will reduce it to 28GB and you the rest of the space (1.7GB) for swap. That should be more than enough.

Now in order to avoid tedious calculations, and make sure the filesystem on sda2 takes all available space on the partition we are going to use this trick:

  • Resize the sda2 filesystem to 27GB.
  • Resize the sda2 partition to 28GB.
  • Resize the sda2 filesystem to all available space of the sda2 partition (28GB).

Temporarily resize sda2

  1. First force check the filesystem for errors:

    $ sudo e2fsck -f /dev/sda2

    If it finishes without errors move to the next step

  2. Resize the filesystem to 27GB:

    $ sudo resize2fs /dev/sda2 27G
  3. Verify the result:

    $ sudo dumpe2fs  /dev/sda2 | grep Block | head -2
    dumpe2fs 1.42.12 (29-Aug-2014)
    Block count:              7077888
    Block size:               4096
    $ echo '(7077888 * 4096)/1024/1024/1024' | bc -l

    Exactly 27GB.

Resize the sda2 partition

To resize the sda2 partition we will delete it temporarily and recreate it using the same START_SECTOR but a different END_SECTOR.

  1. To calculate the new end sector you can use this formula:


    $ echo "206848+62326448*28/29.7" | bc -l

    We can round up the NEW_END_SECTOR to 58965789.

  2. Use fdisk to resize the partition:

    • Delete the sda2 partition:

      $ sudo fdisk /dev/sda
      Changes will remain in memory only, until you decide to write them.
      Be careful before using the write command.
      Command (m for help): d
      Partition number (1,2, default 2): 2
      Partition 2 has been deleted.

      Verify that sda2 is deleted:

      Command (m for help): p
      Disk /dev/sda: 29,8 GiB, 32017047552 bytes, 62533296 sectors
      Units: sectors of 1 * 512 = 512 bytes
      Sector size (logical/physical): 512 bytes / 512 bytes
      I/O size (minimum/optimal): 512 bytes / 512 bytes
      Disklabel type: dos
      Disk identifier: 0xa5161f73
      Device     Boot Start    End Sectors  Size Id Type
      /dev/sda1  *     2048 206847  204800  100M  c W95 FAT32 (LBA)

      It is deleted, but not really until you issue the write command.

    • Create a smaller sda2 partition:

      Command (m for help): n
      Partition type
         p   primary (1 primary, 0 extended, 3 free)
         e   extended (container for logical partitions)
      Select (default p): p
      Partition number (2-4, default 2): 
      First sector (206848-62533295, default 206848): 
      Last sector, +sectors or +size{K,M,G,T,P} (206848-62533295, default 62533295): 58965789
      Created a new partition 2 of type 'Linux' and of size 28 GiB.      

      For the end sector we use the value of the NEW_END_SECTOR we have calculated earlier. Now let’s verify the new partition:

      Command (m for help): p
      Disk /dev/sda: 29,8 GiB, 32017047552 bytes, 62533296 sectors
      Units: sectors of 1 * 512 = 512 bytes
      Sector size (logical/physical): 512 bytes / 512 bytes
      I/O size (minimum/optimal): 512 bytes / 512 bytes
      Disklabel type: dos
      Disk identifier: 0xa5161f73
      Device     Boot  Start      End  Sectors  Size Id Type
      /dev/sda1  *      2048   206847   204800  100M  c W95 FAT32 (LBA)
      /dev/sda2       206848 58965789 58758942   28G 83 Linux
    • Create a new partition of type swap:

      Command (m for help): n
      Partition type
         p   primary (2 primary, 0 extended, 2 free)
         e   extended (container for logical partitions)
      Select (default p): p
      Partition number (3,4, default 3): 
      First sector (58965790-62533295, default 58966016): 
      Last sector, +sectors or +size{K,M,G,T,P} (58966016-62533295, default 62533295): 
      Created a new partition 3 of type 'Linux' and of size 1,7 GiB.
      Command (m for help): t
      Partition number (1-3, default 3): 3
      Partition type (type L to list all types): 82
      Changed type of partition 'Linux' to 'Linux swap / Solaris'.

      Verify that the new partition is created:

      Command (m for help): p
      Disk /dev/sda: 29,8 GiB, 32017047552 bytes, 62533296 sectors
      Units: sectors of 1 * 512 = 512 bytes
      Sector size (logical/physical): 512 bytes / 512 bytes
      I/O size (minimum/optimal): 512 bytes / 512 bytes
      Disklabel type: dos
      Disk identifier: 0xa5161f73
      Device     Boot    Start      End  Sectors  Size Id Type
      /dev/sda1  *        2048   206847   204800  100M  c W95 FAT32 (LBA)
      /dev/sda2         206848 58965789 58758942   28G 83 Linux
      /dev/sda3       58966016 62533295  3567280  1,7G 82 Linux swap / Solaris

      Seems OK.

    • Write changes and exit:

      Command (m for help): w
      The partition table has been altered.
      Calling ioctl() to re-read partition table.

      Remember that nothing is changed unless you issue the write command. If you make a mistake, just hit Ctrl+c and no harm done.

  3. Resize the filesystem to the full size of the partition:

    • Force check the filesystem

      $ sudo e2fsck -f /dev/sda2
    • Resize the filesystem to occupy all the available space in the partition:

      $ sudo resize2fs /dev/sda2

      Running resize2fs without a size definition, extends the size of the filesystem to the size of the partition.

    • Verify the new filesystem size:

      $ sudo dumpe2fs  /dev/sda2 | grep Block | head -2
      dumpe2fs 1.42.13 (17-May-2015)
      Block count:              7344867
      Block size:               4096

      The size in bytes is BLOCK_COUNT * BLOCK_SIZE i.e. 7344867 * 4096 = 30084575232. The size in GB is:

      $ echo '(7344867 * 4096)/1024/1024/1024' | bc -l

Restart into your internal drive

At this point we need to restart into the Operating System installed on the internal SATA device and check if everything works:

$ sudo fdisk -l /dev/sda
Disk /dev/sda: 29,8 GiB, 32017047552 bytes, 62533296 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xa5161f73

Device     Boot    Start      End  Sectors  Size Id Type
/dev/sda1  *        2048   206847   204800  100M  c W95 FAT32 (LBA)
/dev/sda2         206848 58965789 58758942   28G 83 Linux
/dev/sda3       58966016 62533295  3567280  1,7G 82 Linux swap / Solaris

The partition table appears to be correct. But we haven’t formatted the swap partition yet:

$ free
            total       used       free     shared    buffers     cached
Mem:       2006476     264380    1742096      20100      21568     107800
-/+ buffers/cache:     135012    1871464
Swap:            0          0          0

We need to format the swap partition before we can use it.

Setup the swap partition

  1. Format the swap partition:

    $ sudo mkswap /dev/sda3
    mkswap: /dev/sda3: warning: wiping old swap signature.
    Setting up swapspace version 1, size = 1,7 GiB (1826443264 bytes)
    no label, UUID=fa1e99ff-a9ab-4fd7-ba81-e5020f4e604b

    Take a note of the UUID: fa1e99ff-a9ab-4fd7-ba81-e5020f4e604b

  2. Activate swap:

    $ sudo swapon /dev/sda3
  3. Verify swap (in human readable form this time):

    $ free -m
                total       used       free     shared    buffers     cached
    Mem:          1959        259       1700         19         21        105
    -/+ buffers/cache:        132       1826
    Swap:         1741          0       1741

    So we have a total of 1741MB of swap space.

  4. Setup persistent swap.

    To have swap activated persistently across reboots, we need to set it up in /etc/fstab:

    # echo 'UUID="fa1e99ff-a9ab-4fd7-ba81-e5020f4e604b" none swap defaults 0 0' >> /etc/fstab

    You need to run the above command as root.

Now after you reboot you can check with free to see if the swap space is activated.

Yet another practical packaging session, this ine on how to build a Debian package from scratch. This one too is based on the packaging tutorial and practical sessions of Lucas Nussbaum.

We are going to download the source code of gnujump from upstream, and use the pbuilder tool to package it. The advantages of pbuider is that it creates a minimal chroot jail that helps you track any dependencies you might forgot to specify in debian/control. Also it gives you the opportunity to build Debian packages on Ubuntu and vice-versa. You can also build packages for releases other than your own.


  • A recent Debian or Ubuntu system.

Preparation of the pbuilder jail

Install pbuilder and relevant packages:

$ sudo apt-get -y install pbuilder debootstrap devscripts packaging-dev debian-keyring

Prepare the target environment. For example for Ubuntu trusty use can use this setup:

$ sudo pbuilder create --debootstrapopts --variant=buildd --mirror --distribution trusty --architecture amd64 --components main --debbuildopts -mJohn Doe \<\>

Prepare the new package

  1. Download the source:

    $ wget
  2. Extract the archive and change into the source tree:

    $ tar xvzf gnujump-1.0.8.tar.gz
    $ cd gnujump-1.0.8/

Prepare for debian packaging

  1. We are going to use the dh_make utility to prepare the debian directory and all the necessary files:

    $ DEBFULLNAME="John Doe" DEBEMAIL="" dh_make -s -y --createorig

    Check if all necessary files are there:

    $ find debian/

    Now Check the contents of the debian/changelog, debian/rules and debian/control files.

  2. We will need to make some changes in the debian/control file:

    Source: gnujump
    Section: games
    Priority: optional
    Maintainer: John Doe 
    Build-Depends: debhelper (>= 9), autotools-dev, libsdl1.2-dev, libsdl-image1.2-dev, libsdl-mixer1.2-dev
    Standards-Version: 3.9.5

    The libsdl1.2-dev, libsdl-image1.2-dev and libsdl-mixer1.2-dev have been discovered by repeatedly compiling and failing until you get it right. The you can use the apt-cache search and apt-file search commands to discover the packages corresponding to the missing dependencies.

  3. Edit the debian/rules file to look like this:

    DH_VERBOSE = 1
    include /usr/share/dpkg/
    export DEB_BUILD_MAINT_OPTIONS = hardening=+all
    export DEB_CFLAGS_MAINT_APPEND  = -Wall -pedantic
    export DEB_LDFLAGS_MAINT_APPEND = -Wl,--as-needed
           dh $@  --with autotools-dev
    CFLAGS += -lm
  4. Edit the debian/changelog, with dch -e, to like this:

    gnujump (1.0.8-1) unstable; urgency=low
     * Initial release
    -- John Doe<>  Mon, 22 Jun 2015 17:41:22 +0300

Build the package

Run this command from the source tree:

$ pdebuild

Give your password when asked. pdebuild will download and install all dependencies in the pbuilder jail and then build the package. Changes will be lost from the jail, the next time you use it but if all goes well, you should see these files under /var/cache/pbuilder/result:

$ ls -la /var/cache/pbuilder/result/
total 5776
drwxr-xr-x 2 root      root         4096 Ιούν 22 17:52 .
drwxr-xr-x 9 root      root         4096 Ιούν 22 11:26 ..
-rw-r--r-- 1 john john    1449 Ιούν 22 17:52 gnujump_1.0.8-1_amd64.changes
-rw-r--r-- 1 john john 1560574 Ιούν 22 17:52 gnujump_1.0.8-1_amd64.deb
-rw-rw-r-- 1 john john    9228 Ιούν 22 17:52 gnujump_1.0.8-1.debian.tar.xz
-rw-rw-r-- 1 john john     885 Ιούν 22 17:52 gnujump_1.0.8-1.dsc
-rw-rw-r-- 1 john john 2508641 Ιούλ 24  2012 gnujump_1.0.8.orig.tar.gz
-rw-rw-r-- 1 john john 1814056 Ιούν 22 17:41 gnujump_1.0.8.orig.tar.xz

Checking the result

  1. View the information related to the package file:

    $ dpkg -I /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb
    new debian package, version 2.0.
    size 1560574 bytes: control archive=5550 bytes.
        419 bytes,    11 lines      control              
      18390 bytes,   233 lines      md5sums              
    Package: gnujump
    Version: 1.0.8-1
    Architecture: amd64
    Maintainer: John Doe 
    Installed-Size: 2355
    Depends: libc6 (>= 2.14), libgl1-mesa-glx | libgl1, libsdl-image1.2 (>= 1.2.10), libsdl-mixer1.2, libsdl1.2debian (>= 1.2.11)
    Section: games
    Priority: optional
    Description: <insert up to 60 chars description>
     <insert long description, indented with spaces>

As you can see our work is not finished. We need to add a description in debian/control and rebuild it.

  1. Check the contents of the package file:

    $ dpkg -I /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb

Install the package

Now we can install the package:

$ sudo dpkg -i /var/cache/pbuilder/result/gnujump_1.0.8-1_amd64.deb

Now run the gnujump software and check if it works.

This is not the whole story of course. You have to check the package against Lintian to see if it complies with the Debian Policy. And if it’s not compliant, you may need to use Quilt to patch it. You will need to fill debian/watch so you can track updates on the upstream with uscan. The work of a Debian packager never ends.


This guide is a practical session on how to modify an existing debian package, when the version is not included in the current release. It is based on the excellent packaging tutorial and practical sessions of Lucas Nussbaum.

We are going to download a source deb package, build it without modifications, modify it, patch it, rebuild it and in the end, install it in our system.


  • A recent Debian or Ubuntu system.

Installation of development packages

$ sudo apt-get -y install build-essential debhelper devscripts packaging-dev debian-keyring

Get the source from the debian repos

$ dget

After that you should see these files under the current directory:

$ ls
grep_2.21-1.debian.tar.bz2  grep_2.21-1.dsc  grep_2.21.orig.tar.xz
  • grep_2.21-1.dsc: Package’s debian source control file.
  • grep_2.21.orig.tar.xz: Original source.
  • grep_2.21-1.debian.tar.bz2: Debian files and patches.

Unpack the source

The dpkg-source file will unpack the original and debian tarballs and apply the debian patches, if available.

$ dpkg-source -x grep_2.21-1.dsc

Download build dependencies

$ sudo apt-get -y build-dep grep

Build the unmodified package

Change into the source tree and run debuild. We are using the -us and -uc flags to suppress warnings about signing.

$ cd grep-2.21/
$ debuild -us -uc

It doesn’t take long before this package is build. In the parent directory you will find three more files:

  • grep_2.21-1_amd64.deb: the newly created deb package file.
  • the build log. You can use this to check for errors or warnings.
  • grep_2.21-1_amd64.changes: Debian applied changes.

Modify the package

I suggest you do not touch the source, unless you fancy spending your day debugging. We will simply make some modifications on the debian/changelog and debian/rules files.

  1. Add the --with-gnu-ld flag in the DEB_CONFIGURE_EXTRA_FLAGS line of the debian/rules file.

    The --with-gnu-ld is a trivial change and shouldn’t break anything during build. Find this line:

    DEB_CONFIGURE_EXTRA_FLAGS += --without-included-regex

    And change it to this:

    DEB_CONFIGURE_EXTRA_FLAGS += --without-included-regex --with-gnu-ld
  2. Update the changelog file.

    We are going to use the dch utility which is simply a wrapper around your default editor, with changelog syntax checking. Run the following command in the source tree:

    $ DEBFULLNAME="John Doe" DEBEMAIL="" dch -i

    Make the following changes (in bold) the debian/changelog file:

    grep (2.21-1ubuntu1) experimental; urgency=low
     * Support for GNU ld linker.
    -- John Doe   Fri, 19 Jun 2015 13:01:37 +0300

    Note how the name and email of the patcher have been automatically inserted in the changelog entry. That’s because we defined the DEBFULLNAME and DEBEMAIL variables in the shell that runs dch.

Rebuild the modified package

$ debuild -us -uc

You will see the following error:

dpkg-source: error: aborting due to unexpected upstream changes, see /tmp/grep_2.21-1ubuntu1.diff.eYCcPk
dpkg-source: info: you can integrate the local changes with dpkg-source --commit
dpkg-buildpackage: error: dpkg-source -b grep-2.21 gave error exit status 2
debuild: fatal error at line 1376:

The above error happens because the --with-gnu-ld flag makes changes to the upstream source and this is against the Debian policy.

Apply patches for Policy compliance

$ cp /tmp/grep_2.21-1ubuntu1.diff.eYCcPk debian/patches/90-enable-gnu-ld.patch
$ echo 90-enable-gnu-ld.patch >> debian/patches/series

It is considered a good practice to edit the patch, add a description and a short summary and fill the headers related to the Patch Tagging Guidelines.

This method is only a workaround. The correct way to deal with patches is Quilt.

Final rebuild of the modified package

$ debuild -us -uc

You will see five additional files in the parent directory:

  • grep_2.21-1ubuntu1_amd64.deb: the new deb package file.
  • grep_2.21-1ubuntu1.debian.tar.bz2: the new debian directory tarball.
  • grep_2.21-1ubuntu1.dsc: the new debian source control file.
  • the build log.
  • grep_2.21-1ubuntu1_amd64.changes: the changes file.

Checking the differences between original and new

The following commands will find the differences in the debian source control and changes files:

$ diff ../*.changes
$ diff ../*dsc

Install the new package

$ sudo debi

Check if grep is the correct version:

$ grep --version
grep (GNU grep) 2.21
Copyright (C) 2014 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later .
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Mike Haertel and others, see .

All done. If you have reached so far congratulations! You have successfully rebuilt a Debian package.


More than a year or so, I have been the proud owner of a first generation Utilite ARM appliance. But the harsh Cyprus summer, hit it hard and the microSD circuit stop working. I could no longer boot alternative systems on microSD cards. All I was left with, was the stock system with an aging Ubuntu 12.04 ARM port.

Enter the U-Boot

Das U-Boot is a boot loader that targets mostly embedded systems. Many ARM appliances, including the Utilite, are using U-Boot to boot their OS.

I entered the U-Boot environment to do some checks about the mmc issue. To do that just press the ‘any‘ key when you see the following message:

Hit any key to stop autoboot:

Then type the following command in your U-boot terminal:

CM-FX6 # mmc info
Card did not respond to voltage select!

That message does not look very healthy! When I tried to insert a microSD card, I got this message repeatedly, in the U-Boot terminal:

EHCI timed out on TD - token=0x80008c80

The keyboard stopped responding and I had no other option than to force restart. I think now we have enough evidence to say that the microSD circuitry went FUBAR. At this point you should probably contact CompuLab for a replacement.

But this is not what I did. The appliance has 3 USB ports available, so why not use them? This will have the added benefit of USB devices being more accessible, than the hard to access microSD slot.

Well, the original U-Boot image that the Utilite was shipped with, did not had USB boot support. This has long changed and the nice folks at CompuLab have built a newer version that supports booting from USB storage devices.

Upgrading U-Boot

First download the most recent U-Boot updater on your Utilite appliance:

$ wget

Check the MD5 sum:

$ echo a79e492f3eb626c770c5185cda0edfec ; md5sum utilite-updater.tar.bz2 
a79e492f3eb626c770c5185cda0edfec  utilite-updater.tar.bz2

Extract the archive:

$ tar xvjf utilite-updater.tar.bz2

Run the updater:

$ sudo ./ 

CompuLab CM-FX6 (Utilite) boot loader update utility 2.2 (Feb 8 2015)

>> Checking for utilities... 
>> ...Done 
>> Checking that board is CM-FX6 (Utilite)... 
>> ...Done 
Please input firmware file path (or press ENTER to use "cm-fx6-firmware"): 

Just press ‘Enter’ after the above prompt. Then answer ‘Yes’ (y) to the following questions:

>> Looking for boot loader image file: cm-fx6-firmware 
>> ...Found 
>> Looking for SPI flash: mtd0 
>> ...Found 
>> Current U-Boot version in SPI flash: U-Boot 2014.10-cm-fx6-2.1 (Jan 19 2015 - 11:28:10) 
>> New U-Boot version in file:      U-Boot 2014.10-cm-fx6-2.1 (Jan 19 2015 - 11:28:10) (500K) 
>> Proceed with the update? 
1) Yes
2) No
#? y  
** Do not power off or reset your computer!!! 
>> Erasing SPI flash... 
Erasing 4 Kibyte @ bf000 -- 100 % complete 
>> ...Done 
>> Writing boot loader to the SPI flash... 
>> ...Done 
>> Checking boot loader in the SPI flash... 
>> ...Done 
>> Boot loader update succeeded!

** Resetting U-Boot environment will override any changes made to the environment! 
>> Reset U-Boot environment (recommended)? 
1) Yes
2) No
#? y
>> U-boot environment will be reset on restart. 
>> Done!

Then reboot the appliance:

$ sudo reboot

It is a good idea to keep a backup of the original U-Boot configuration for future reference:

$ sudo fw_printenv > utilite.uboot.orig

Enhancing the USB boot setup

If you study the above U-Boot setup you will find that the USB config works only if you have an option boot.scr script under the first partition of your USB. This excludes USB drives with only the uImage file. That means that you cannot even boot the Utilite SSD installer if you burn it on USB, since it does not have a boot.scr script.

I’ve been playing around with the U-Boot environment and I came out to this configuration:

setenv bootcmd run setupmmcboot;mmc dev ${storagedev};if mmc rescan; then run trybootsrz;fi;run setupusbboot;if usb start; then if run loadscript; then run bootscript;else run usbbootargs;if run loadkernel; then run doboot;else setenv bootargs;fi;fi;fi; run setupsataboot;if sata init; then run trybootsmz;fi;run setupnandboot;run nandboot;
setenv usbroot /dev/sdb2
setenv usbrootdelay=1
setenv usbbootargs=setenv bootargs root=${usbroot} rootdelay=${usbrootdelay}

If you don’t want to configure the above commands manually, you can download my custom U-boot environment updater and the patch I prepared:

Download the U-Boot environment update shell script:

$ wget
$ chmox +x

Download the U-boot custom configuration:

$ wget

Now load the custom configuration into the U-Boot environment:

$ sudo ./ setup-usb-boot-utilite.uboot

If something goes wrong you can restore your original configuration using the original configuration we saved earlier:

$ sudo ./ utilite.uboot.orig

The U-Boot environment updater will also create a backup file, with the current U-Boot environment configuration, just before the update:

$ ls *.bak

Test with the Utilite SSD installer

Now it is time to test our new configuration.

First download the SSD installer:

$ wget

Check the MD5 sum:

$ echo 82eeb54c4d5245c60fd82c3e983d10e9 ; md5sum cl-installer_utilite-2_kernel-6.3_2014-12-17.img.xz
82eeb54c4d5245c60fd82c3e983d10e9  cl-installer_utilite-2_kernel-6.3_2014-12-17.img.xz

Extract it:

$ unxz cl-installer_utilite-2_kernel-6.3_2014-12-17.img.xz

This will extract a cl-installer_utilite-2_kernel-6.3_2014-12-17.img image file in the working directory.

Now comes the tricky part. We will load the image in a USB device. Make sure you choose the correct device! The dd tool we are using below, is a heartless beast that will chew the data out of every device you select in its of= flag. If by mistake you give your internal disk instead of the USB, you will lose your partitions and data! You have been warned!

So after you select a USB (one that does not have any data you need) insert it in your Linux workstation. Then try the following check to find out the device name of the USB drive:

$ dmesg | tail -n20
[61425.197050] mce: [Hardware Error]: Machine check events logged
[71124.693498] compiz[1853]: segfault at 80000000 ip 0000000080000000 sp 00007ffc438c50a8 error 14
[73897.971544] usb 1-2: new high-speed USB device number 10 using xhci_hcd
[73898.105247] usb 1-2: New USB device found, idVendor=0951, idProduct=1665
[73898.105254] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[73898.105257] usb 1-2: Product: DataTraveler 2.0
[73898.105260] usb 1-2: Manufacturer: Kingston
[73898.105262] usb 1-2: SerialNumber: 50E54951351BBE70A9455C5B
[73898.106083] usb-storage 1-2:1.0: USB Mass Storage device detected
[73898.106370] scsi host8: usb-storage 1-2:1.0
[73899.187591] scsi 8:0:0:0: Direct-Access     Kingston DataTraveler 2.0 PMAP PQ: 0 ANSI: 6
[73899.187848] sd 8:0:0:0: Attached scsi generic sg2 type 0
[73900.521857] sd 8:0:0:0: [sdb] 15335424 512-byte logical blocks: (7.85 GB/7.31 GiB)
[73900.522528] sd 8:0:0:0: [sdb] Write Protect is off
[73900.522531] sd 8:0:0:0: [sdb] Mode Sense: 23 00 00 00
[73900.523124] sd 8:0:0:0: [sdb] No Caching mode page found
[73900.523126] sd 8:0:0:0: [sdb] Assuming drive cache: write through
[73900.562834]  sdb: sdb1 sdb2
[73900.565248] sd 8:0:0:0: [sdb] Attached SCSI removable disk
[73903.203134] EXT4-fs (sdb2): mounted filesystem with ordered data mode. Opts: (null)

So the device name is sdb and it has two partitions: sda1 and sda2. Check if these partitions have been mounted automatically:

$ mount | grep sdb
/dev/sdb2 on /media/theodotos/rootfs type ext4 (rw,nosuid,nodev,relatime,data=ordered,uhelper=udisks2)
/dev/sdb1 on /media/theodotos/boot type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)

They are mounted. We need to unmount them before dumping the image on the device:

$ sudo umount /dev/sdb1 /dev/sdb2

Now we are ready to run dd (device dump) against the USB drive:

$ sudo dd if=~/Downloads/cl-installer_utilite-2_kernel-6.3_2014-12-17.img of=/dev/sdb bs=1M

You are not going to see any progress bar during the device dump. Just be patient and let the utility take its time.

After dd finishes and returns back to the shell, safely remove the USB drive and try it on Utilite. If you reboot the appliance you should see the LXDE desktop of the Utilite installer. Unplug it and you are back to your Ubuntu, on the internal drive.


The KVM hypervisor is a virtualization system included with the Linux kernel. Along with XEN is one of the most attractive virtualization platforms based on Linux.

KVM offers several advantages over the more user-friendly, VirtualBox. Since it is integrated into the mainstream Linux kernel, it boasts significant performance benefits[1]. Furthermore it is better suited as a virtualization platform solution while VirtualBox is better suited for short-term tests and casual, user owned, VMs. KVM supports many guest operating systems so you can use Linux, Unix, Windows or something more exotic.

Install KVM on your system

  1. Make sure your system supports KVM.

    KVM is only supported on systems with Hardware-Assisted Virtualization. If your system does not support HAV you can revert to QEMU, a system which KVM is based on.

    • First install CPU checker:

      $ sudo apt-get -y install cpu-checker
    • Check if KVM is supported:

      $ kvm-ok
      INFO: /dev/kvm exists
      KVM acceleration can be used

      Looks OK. Still you may need to check your BIOS/EFI whether this feature is enabled.

  2. Install KVM:

    $ sudo apt-get -y install qemu-kvm

KVM Basic Usage

You can use KVM directly. This method is suitable for testing or troubleshooting but not appropriate for production VMs.

  1. Create a disk image:

    $ qemu-img create -f qcow2 testvm.qcow2 20G
    Formatting 'testvm.qcow2', fmt=qcow2 size=21474836480 encryption=off cluster_size=65536 lazy_refcounts=off

    The qcow2 format grows dynamically so it does not really occupy 20GB:

    $ ls -lh testvm.qcow2 
    -rw-r--r-- 1 theo theo 193K Μάι  14 18:43 testvm.qcow2
  2. Start a VM instance, to setup your system:

    $ kvm -m 1024 -hda testvm.qcow2 -cdrom ~/Downloads/ubuntu-15.04-desktop-amd64.iso -boot d -smp 2

    The options are explained below:

    • -m: memory in MB
    • -hda: first disk image to use
    • -cdrom: you can use an .iso file (ubuntu-15.04-desktop-amd64.iso) or a physical CD-ROM (/dev/sr0).
    • -boot: choose where to boot from. A parameter of d tells KVM to use the cdrom for booting.
    • -smp: Stands for Symmetric Multiprocessing. 2 is the number of CPUs available to the VM.

    After you run the command above you will get a window with your VM running in it:

    KVM VM

    This window will capture your mouse and keyboard when you work in it. If you want to return to your host OS just press Ctrl-Alt together and they will both be released.

  3. Run your VM.

    After the installation is finished you can run your VM from the disk image.

    • First let’s check the size of your disk:

      $ ls -lh testvm.qcow2 
      -rw-r--r-- 1 theodotos theodotos 5,9G Μάι  14 19:33 testvm.qcow2

      So after the installation of Ubuntu Desktop 15.04 (Vivid Vervet) the disk image has grown to 5.9GB.

    • Run the VM from the disk image:

      $ kvm -m 1024 -hda testvm.qcow2 -smp 2

      A new window will pop up with the freshly installed OS.

Running KVM under libvirt

The libvirt system, is a platform for running VMs under many different hypervisors using a common API and toolset. It supports KVM, XEN, QEMU, VirtualBox and many others. This is the preferred method of using KVM because the VMs are globally available to privileged (local and remote) users, it facilitates VM management and you can configure autostart and many other features.

  1. Setting up libvirt:

    $ sudo apt-get -y install libvirt-bin
  2. Give appropriate permissions to the users expected to manage your VMs:

    $ sudo usermod -a -G libvirtd theo

    The theo will be added as a member in the libvirtd group. After that you will need to log-out, for the permission to be activated.

Creating a libvirt ready VM

There are many tools to create VMs for libvirt. In this section we are going to examine two of them: virt-install and uvtool.

  1. Using virt-install.

    The advantage of virt-install is being distro agnostic. That means you can use it to install Debian, Ubuntu, RHEL, CentOS, Fedora, SUSE and many other distros as well.

    • Install virt-install:

      $ sudo apt-get -y install virtinst
    • Create a machine:

      $ sudo virt-install -n testvm -r 512 --disk path=/var/lib/libvirt/images/testvm.img,bus=virtio,size=4 -c ~/Downloads/ubuntu-14.04.2-server-amd64.iso --network network=default,model=virtio --graphics vnc,listen= --noautoconsole -v
      Starting install... Allocating 'testvm.img' | 4.0 GB 00:00 Creating domain... | 0 B 00:01 Domain installation still in progress. You can reconnect to the console to complete the installation process.
      • -n: VM name
      • -r: RAM in MB
      • –disk: Path for the virtual disk.
      • -c: defive the .iso file or CDROM device to use for the OS installation.
      • –network: Select your preferred networking mode.
      • –graphics: Select the graphics protocol. We are using VNC here that allows connections only from localhost. You can use the (any) instead if IP to allow connections from elsewhere.
      • –noautoconsole: do not run the guest console.

    • Connect to the VM and setup the guest OS:

      $ xtightvncviewer

      The VNC client will connect to the default VNC port which is 5900. You can append ::<PORT> to the hostname or IP address if you want to use a different port, e.g. xtightvncviewer

      If xtightvncviewer is not installed you can install it with sudo apt-get install xtightvncviewer. You can also use a graphical VNC client like Remmina.

    • Verify that the machine is created:

      $ virsh list --all
      Id    Name                           State
      -     testvm                         shut off

      The machine will appear as shut off after the OS setup finishes.

    • Start the VM:

      $ virsh start testvm
      Domain testvm started
    • Verify that the VM is started:

      $ virsh list
      Id    Name                           State
      3     testvm                         running
  2. Install a VM using uvtool:

    The uvtool is a tool to create minimal VMs. Unlike virt-install you can create only Ubuntu VMs but the overall setup is taken care by uvtool.

    • Install uvtool:

      $ sudo apt-get -y install uvtool uvtool-libvirt
    • Create a local repository of ubuntu-cloud images:

      $ uvt-simplestreams-libvirt sync release=trusty arch=amd64

      This command will download the trusty (14.04) release locally.

    • Query for local repository

      $ uvt-simplestreams-libvirt query
      release=trusty arch=amd64 label=release (20150506)
    • Generate an ssh key pair (unless you already have one):

      $ ssh-keygen -b 4096
    • Create a uvt based VM:

      $ uvt-kvm create --cpu 2 --memory=1024 --disk=10 testuvt

      This will create a trusty VM with 2 CPUs, 1GB RAM and 10 GB disk.

    • Verify the machine creation:

      $ virsh list
      Id    Name                           State
      5     testuvt                        running
    • Connect to your VM:

      $ uvt-kvm ssh testuvt --insecure

      You can get root access, on the VM, with sudo -i.

Managing libvirt using the graphical Virtual Machine Manager

Virtual Machine Manager is a front-end to libvirt. It help system administrators managing their VMs using a convenient graphical interface.

  1. Installing Virtual Machine Manager:

    $ sudo apt-get -y install virt-manager
  2. Running Virtual Machine Manager:

    • You can find it in the application menu or run virt-manager from the command line. virt-manager-1.png As you can see the two VMs we created earlier, are already there.

  3. Creating a new machine.

    • Press the Create a new machine icon: virt-manager-2.png

  4. New VM options.

    • Select one of the following option to continue: virt-manager-3.png Each option provides different steps. You may need to read the documentation for all the details. The first option is the most straight forward.

Managing your VMs with virsh

  1. Listing machines.

    • List only running machines:

      $ virsh list
      Id    Name                           State
      5     testuvt                        running
    • List all machines:

      $ virsh list --all
      Id    Name                           State
      5     testuvt                        running
      -     testvm                         shut off
  2. Starting machines:

    $ virsh start testvm
    Domain testvm started
  3. Shutdown machines:

    $ virsh shutdown testvm
    Domain testvm is being shutdown
  4. Restart machines:

    $ virsh reboot testuvt
    Domain testuvt is being rebooted
  5. Set machines to autostart:

    • Enable autostart:

      $ virsh autostart testuvt
      Domain testuvt marked as autostarted
    • Disable autostart

      $ virsh autostart --disable testuvt
      Domain testuvt unmarked as autostarted
  6. Other useful virsh commands:

    • console: get console access to a VM.
    • destroy: destroy (delete) a machine.
    • dominfo: get the machine details.
    • migrate: migrate a machine to another libvirt host.
    • save: save the machine state.
    • snapshot-create: create a snapshot of the machine.

    To see all the supported commands you can run virsh --help.

Learning to use libvirt is of great value to a Linux sysadmin because the same commands apply for KVM, XEN, VirtualBox, even container systems like OpenVZ and LXC.


Cisco Packet Tracer is network simulation program for students in the Cisco Networking Academy. There is an Ubuntu version for it and we are going to show you how to install it and configure it.

This is tested on Ubuntu 15.10 (Vivid Vervet) but it should work on earlier versions. A requirement for this guide is to have root access on the target machine or sudo admin rights.

Download Cisco Packet Tracer

If you have an account on the Cisco Networking Academy you can download Packet Tracer from Student Resources. Ask your instructor if you can’t find it.

After you download it, it should be in your Downloads folder:

$ ls -l ~/Downloads/
total 183928
-rw-r-----  1 theo theo 188328996 Jan  31 03:34 Cisco Packet Tracer 6.2 for Linux - Ubuntu installation - Instructor version.tar.gz

Students can download the student version instead.

Unpack the package

  1. Change into the Downloads directory:

    $ cd ~/Downloads/
  2. Unpack the downloaded file:

    $ tar xvzf Cisco\ Packet\ Tracer\ 6.2\ for\ Linux\ -\ Ubuntu\ installation\ -\ Instructor\ version.tar.gz
  3. Verify the unpacked files:

    $ ls -l
    total 183932
    -rw-r-----  1 theo theo 188328996 Ιαν  31 03:34 Cisco Packet Tracer 6.2 for Linux - Ubuntu installation - Instructor version.tar.gz
    drwxr-xr-x 12 theo theo      4096 Ιαν  30 01:00 PacketTracer62

    The installation files are under the PacketTracer62 directory.

Install Packet Tracer

  1. Change into the PacketTracer62 directory:

    $ cd PacketTracer62
  2. Run the installer:

    $ sudo ./install
    • Press the ‘Enter‘key to accept the EULA.
    • Press ‘Space‘ repeatedly to reach 100%.
    • Type ‘y‘ (yes) to accept the EULA.
    • Type the location where you want the package installed. If you just press ‘Enter‘ it will choose the default (/opt/pt).
    • When asked to create a symbolic link “packettracer” in /usr/local/bin type y (yes).

  3. Setup the Packet Tracer Desktop Link:

    While you are in the PacketTraser62 directory, copy the PT Desktop link to your Desktop and assign executable permissions on it:

    $ cp bin/Cisco-PacketTracer.desktop ~/Desktop/
    $ chmod +x ~/Desktop/Cisco-PacketTracer.desktop

    Unfortunately the links to the program and its icon are wrong. Edit the Exec and Icon directives in the Cisco-PacketTracer.desktop file as follows:

    # Exec=/usr/local/PacketTracer6/packettracer
    # Icon=/usr/local/PacketTracer6/art/app.png

    Alternatively you can just type the packetracer command from your terminal.

Although Packet Tracer is based on several Free Software libraries, it is not Free Software itself. I hope its Cisco developers see the light and release this great learning tool as Free Software. Only good things can come from such decision.