Migrating a virtual machine from VirtualBox to VMware Player on Linux

The progress of Windows 10 is something that I have been watching. Early signs have been promising and the most recent live event certainly contained its share of excitement. The subsequent build that was released was another step in the journey though the new Start Menu appears more of a work in progress than it did in previous builds. Keeping up with these advances sometimes steps ahead of VirtualBox support for them and I discovered that again in the last few days. VMware Player seems unaffected so I thought that I’d try a migration of the VirtualBox VM with Windows 10 onto there. In the past, I did something similar with a 32-bit instance of Windows 7 that subsequently got upgraded all the the way up to 8.1 but that may not have been as slick as the latest effort so I thought that I would share it here.

The first step was to export the virtual machine as an OVF appliance and I used File > Export Appliance… only to make a foolish choice regarding the version of OVF. The one that I picked was 2.0 and I subsequently discovered that 1.0 was the better option. The equivalent command line would look like the following (there are two dashes before the ovf10 option below):

vboxmanage export [name of VM] -o [name of file].ova --ovf10

VMware have a tool for extracting virtual machines from OVF files that will generate a set of files that will work with Player and other similar products of theirs. It goes under the unsurprising name of OVF Tool and it usefully works from a command line session. When I first tried it with an OVF 2.0 files, I got the following error and it stopped doing anything as a result:

Line 2: Incorrect namespace http://schemas.dmtf.org/ovf/envelope/2 found.

The only solution was to create a version 1.0 file and use a command like the following (it’s a single line though it wraps over two here and there are two dashes before the lax switch):

ovftool --lax [name of file].ova [directory location of VM files]/[name of file].vmx

The --lax option is needed to ensure successful execution even with an OVF 1.0 file as the input. Once I had done this on my Ubuntu GNOME system, the virtual machine could be opened up on VMware Player and I could use the latest build of Windows 10 at full screen, something that was not possible with VirtualBox. This may be how I survey the various builds of the operating that appear before its final edition is launched later this year.

Automatically enabling your network connection at startup on CentOS 7

The release of CentOS 7 stoked my curiosity so I gave it a go in a VirtualBox virtual machine. It uses GNOME Shell in classic mode so the feel is not too far removed from that of GNOME 2. One thing to watch though is that it needs at least version 4.3.14 of VirtualBox or the Guest Additions kernel drivers will not compile at all. That might sound surprising when you learn that the kernel version is 3.10.x and that for GNOME Shell is 3.8.4. Much like Debian production releases, more established versions are chosen for the sake of stability and that fits in with the enterprise nature of the intended user base. Even with that more conservative approach, the results still please the eye though attempting to change the desktop background picture managed to freeze the machine. Other than that, most things work fine.

Even so, there are unexpected things to be encountered and one that I spotted was that network connectivity needed to switched on every time the VM was started. The default installation gives rise to this state of affairs and it is a known situation with CentOS from at least version 6 of the distribution and is not so hard to fix once you know what to do.

What you need to do is look for the relevant configuration file in /etc/sysconfig/network-scripts/ and update that. Using the ifconfig command, I found that the name of the network interface. Usually, this is something like eth0 but it was enp0s3 in my case so I had to look for a file named ifcfg-enp0s3 and edit that. The text that is sought is ONBOOT=no and that needs to become ONBOOT=yes for network connections to start automatically. To do something similar from the command line, CentOS had suggested the following:

sed -i -e ‘[email protected]^ONBOOT=”[email protected]=”[email protected]’ ifcfg-enp0s3

The above uses sed to do an inline (and case insensitve) edit of the file to change the offending no to a yes, once you have dropped in the /etc/sysconfig/network-scripts/ directory. My edit was done manually with Gedit so that works too. One thing to add is that any file editing needs superuser privileges so switching to root with the su command and using sudo is in order here.

Suppressing Update Notifier messages in Ubuntu GNOME 14.04

Though I use only the command line to do system updates, I still got system restart messages every time a new kernel version was installed. While they can be helpful, I actually prefer to be left to my own devices when it comes to restarting a system and I may have a something running at the time that I do not wish to interrupt.

In Ubuntu GNOME 13.10 and before, there was no sign of these messages so I decided to see if I could go nag free again. The responsible application is called Update Notifier and I tried seeing if I could remove it but that act has a major impact of the system so it was not a useful way to go.

As it happens, it is an application that starts up automatically at computer boot time but there was no sign of an entry for it in the Startup Applications Preferences screen (started using from the command line using gnome-session-properties). The for this is that there is flag called NoDisplay in the relevant autostart shortcut in /etc/xdg/autostart/ that stops it appearing in the aforementioned settings screen when set to true. The trick then is to set it to false and the following command (broken over two lines for sake of display and quotes could need replacing when you issue the command too) does the trick for all such hidden start-up applications:

sudo sed -i ‘s/NoDisplay=true/NoDisplay=false/g’
/etc/xdg/autostart/*.desktop

What the above does is that sed goes into every file and changes NoDisplay=true to NoDisplay=false in each file with the desktop extension. When that has completed, there are more entries in Startup Applications Preferences and Update Notifier can be deselected in order to stop it starting. Removing the relevant .desktop file would be a more permanent change but this one will do me, especially since no more of those pesky restart messages appear anymore. My regularity when it came to system updates meant that the update messages never appeared anyway and I tend to shut down my system at the end of every day so the updates will be picked up too so all should be well.

Dropping back to a full screen terminal session from a desktop one in Linux

There are times when you might need to drop back to a full screen terminal session from a graphical desktop environment when running Linux. One example that I have encountered is the installation of Nvidia’s own graphics drivers on either Ubuntu or Linux Mint. Another happened to me on Arch Linux when a Cinnamon desktop environment update left me without the ability to open up a terminal window. Then, the full screen command allowed me to add in an alternative terminal emulator and Tech Drive-in’s list came in handy for this. there might have been something to sort on a FreeBSD installation that needed the same treatment. This latter pair happened to me on sessions running within VirtualBox and that has its own needs when it comes to dropping into a full screen command line session and I will come to that later.

When running Linux on a physical PC, the keyboard shortcuts that you are CTRL + ALT + F1 for entering a full screen terminal session and CTRL + ALT + F7 for returning to the graphical desktop again. When you are running a Linux guest in VirtualBox and the host operating system also is Linux, then the aforementioned shortcuts do not work within the virtual machine but instead affect the host. To get the guest operating system to drop into a full screen terminal session, the keyboard shortcut you need is [Host Key] + F1 and the default host key is the right hand CTRL key on your keyboard unless you have assigned to something else as I have. The exit the full screen terminal session and return to the graphical desktop again, the keyboard shortcut is [Host Key] + F7.

All of this works with GNOME and Cinnamon desktop environments running in X sessions and I cannot vouch for anything else unless alternatives like Wayland come my way. Hopefully, this useful functionality applies to those other set-ups too because there are times when a terminal session is needed to recover from a mishap, rare though those thankfully are and they need to be very rare if not non-existent for most users.

Fixing Background Image Display in GNOME Shell 3.10

On upgrading from Ubuntu GNOME 13.10 to Ubuntu GNOME 14.04, a few rough edges were to be noticed. One was the display of my chosen background image: it was garbled. Later, I discovered that there is a maximum width of 2560 px for background images in GNOME Shell these days and that things get messy beyond that.

In my case, the image width was around 6000 px and I was used to its getting resized in GNOME Shell 3.8 and its predecessors. It seems that the functionality got removed after that though so the workaround of manual image resizing in the GIMP needed to be employed. Though having big images open in memory creates an additional overhead, not handling them very well at all looks like a bug caused by setting 2560 px as a maximum screen width for the GNOME Shell panel and the complete removal of Nautilus from desktop rendering duties. Let’s hope that sense is seen with ever larger screen sizes and resolutions coming our way.

It’s the sort of thing that did get me looking at adding on Cinnamon 2.2 for a while before setting background image scaling using the indispensable GNOME Tweak Tool was discovered. LinuxG.net has a useful tutorial on this for anyone with such an adventurous streak in them. For now though, I am OK with my set up but the GNOME project’s focus on minimalism could affect us in other ways so I can see why Clem Lefebvre started the Cinnamon one primarily for Linux Mint and the desktop environment is appearing elsewhere too. After all, Gedit lost its menu bar in GNOME 3.12 so it’s just as well that we have alternative choices.

Update 2014-05-06: It seems that the desktop image bug that afflicts GNOME Shell 3.10 got sorted for GNOME Shell 3.12. At least, that is the impression that an Antergos instance in a VirtualBox virtual machine gives me.