As written previously: There are performance benefits to be had by switching from VirtualBox to KVM. And now, after making the switch I can firmly say that not only are the performance benefits noticeable, the configuration of automatic startup and, prima facie, backups, seems to be much easier to establish and use.

I’ve grown very fond of Oracle’s Virtualbox but given that it’s
more of a prosumer product rather than an enterprise one, it’s only  fair that I learn how to use it’s bigger brother KVM.

The process of switching to KVM itself was very simple, all things considered. The process I followed, after troubleshooting the various stages worked like this:

1. Stop and backup all the virtualbox VMs.
2. Convert the virtual disks from a virtualbox to kvm format.
3. Create the virtual machines using virt-manager.
4. Removed vboxtool and configs
5. Create a bridge interface on the KVM Host
6. Set each of the virtual machines to use the new bridge interface to connect to the internet and local network.
7. Configure each VM’s network interface to use the new network interface.

In Detail:

Stopping the machines was easy, simply ssh into them and run shutdown -h now.

Backup the machines using the clone option in VirtualBox.

On the Hypervisor, navigate to the virtual machine directory (usually /home/user/VirtualBox VMs/ and create a new disk image from the vdi files like this:

qemu-img convert -f vdi -O qcow2 VIRTUALBOX.vdi KVM.qcow2

Thanks to this website for the useful tip. At this point I moved each of my VM disks to a new separate directory. This wasn’t strictly necessary, it’s just neater!

Use virt-manager to then create the virtual machines. The process is intuitive. Be sure to enable bringing up at boot. It was at this point that I ran into trouble. By default the virtual machines cannot talk to the host which is a problem if the host is also a file server. To get around this I had to modify the network config on the host. The KVM network page provided information on how to achieve this. Ultimately, you create network bridge then set each of the VMs to use that bridge. Below is my modified interfaces file on my Ubuntu 16.04 VM host:

# The primary network interface
#bridge to allow the VMs and the host to communicate
auto br0
iface br0 inet static
address 10.60.204.130
netmask 255.255.255.128
broadcast 10.60.204.255
gateway 10.60.204.129
dns-nameservers 10.60.204.133 8.8.8.8
dns-search warbelnet.local
bridge_ports enp6s0
bridge_stp off
bridge_maxwait 0
bridge_fd 0

Below is the configuration in virt-manager for the network in one of my VMs:

This was testing and working.

As my virtual machines are all running Ubuntu 16.04 the network interfaces file needed to be updated as the interface name changes after a hardware change.

Finally, I uninstalled Virtualbox, removed vboxtool (which I had been using to automatically start the Virtualbox VMs), removed vboxtool’s config from /etc/ and restarted everything to test.

Very happy to say it’s been quite a success!

This week my wife asked me to create for her a blog. As such I’ve had to rejig the www server to make space for her new domain.

The process is quite simple:

1. Create the new user on the www server so she has sftp access.
2. Create a mailbox, and mysql database for the new user.
3. Create the directory structure, copy the latest wordpress to it and set file permissions.
4. Create the DNS entries in my DNS provider, and locally on my home DNS
5. Copy and edit my blog’s apache config files.
6. Enable the new site -without SSL
7. Update the Let’s Encrypt certificate files with the new domain
8. Enable the SSL website.
9. Configure wordpress.

In detail:

Create a new user on the web server with adduser -D

Depending on your setup, create a new mailbox, if you like and create a new database and user. I use phpmyadmin and postfixadmin for these tasks. Remember to note down the passwords and make them secure! Use a random password generator if needs must.

I created the directory structure in /var/www/bel.warbel.net/ moving forward, I think it would be more secure to have user’s websites stored in their home directories and then have the users jailed to stop access to the wider system. It would also make sense to have the sub domain match their username for simplicity’s sake. Be sure to change ownership once you’ve copied in the latest word press: chown USER:www-data /var/www/bel.warbel.net -R

WordPress (as www-data) will need write permissions on the sub directories particularly in the data directories to allow for downloading plugins and themes. Be sure to chmod g+w those directories.

At this point, if you have not done so already, create the DNS entries for your site. For me this meant updating my internal DNS records with a CNAME for bel.warbel.net to point to www.warbel.net, which I replicated on my own DNS hosts: https://www.noip.com/ who I recommend. As I do not have a static IP address, I use their dyndns services on my router.

Next, I copied the /etc/apache2/sites-available/blog.warbel.net.conf and blog.warbel.net-le-ssl.conf and renamed them to bel.warbel.net.conf and bel.warbel.net-le-ssl.conf respectively. The let’s encrypt program will, initially, not expect to see a SSL site, so I commented out the redirects in the non-ssl file and updated the config file for all the references to the hostname and root directories.

Enable the new site: a2ensite bel.warbel.net; service apache2 reload

Run the ssl certificate generator with all the domains you need:

sudo letsencrypt certonly –webroot -w /var/www/html -d www.warbel.net -w /var/www/bel.warbel.net -d bel.warbel.net -w /var/www/blog.warbel.net -d blog.warbel.net

If successful, it will show you a screen, prompting you to agree to update the certificate with the new domain:

At this point, it is safe and appropriate to enable the ssl site with: a2ensite bel.warbel.net-le-ssl.conf; service apache2 reload

Be sure to edit the non-ssl site’s config and re-enable forced ssl.

Finally, configure the new wordpress site. I found that to enable uploading files (updates etc) I needed to add a line to wp-config.php:

define(‘FS_METHOD’, ‘direct’);

After doing some much needed research into virtualisation on Linux, it’s become apparent that I should migrate my virtual machines from Virtualbox to KVM. KVM has significant performance benefits and it is a solid ‘production’ system. It’s also clear that if I want to advance my technical skills in the enterprise Linux space, then I need to learn more about KVM and implement it on my systems.

I love Virtualbox because it is cross platform- I can create a VM on a Linux host, and move it to a windows host if needed. The remote desktop server built into the program, too, is a very handy feature. However I will admit, that I very rarely will spin up a VM on Linux and move it to another OS (if ever) and since discovering MobaXTerm on windows, I can now easily, from any windows machine (read: my laptops) access the virt-manager X window session of a running VM on KVM. As an aside, MobaXTerm is an amazing program and compliments putty quite nicely!

My concerns so far about the migration are 3 fold:

1. I need to convert the disk images into a native format for KVM and virt-manager to use.
2. I currently automate my VM startup and shutdown with VBoxTool so I will need to either find a preexisting automation solution, or create my own init scripts.
3. Virtualised hardware: Clearly Virtualbox and KVM will virtualise hardware in their own ways, so I need to be sure that the machines can migrate to the new environment and still work. I’m mostly concerned with networking as experience has taught me that Linux is very forgiving of hardware changes, however with the new naming conventions of Ethernet devices, my network configs will need to be updated.

A small project this weekend. I used my hitherto untouched Raspberry Pi 2 as a security system. The process is reasonably straight forward to anyone who is already familiar with the Raspberry Pi.

I have two web cams which are attached to the Pi via an external powered usb hub. This is necessary as the device does not have enough power to run itself and the cameras. It also has a USB 2.4G wireless dongle.

I’ve installed MotionEye onto the Pi’s SD card. Again, simply using:
sudo dd if=MotionEyesIMGFile of=/dev/sdX
did the job.

Once the device was setup using the wired network, it could be secured with an admin password, by default it has no password and it can be added to the wireless network. All of the settings can be accessed by clicking the menu icon in the top left hand corner, and the process is intuitive, as is adding the cameras.

The only real difficulty encountered was allowing it to function behind the reverse proxy. To do so relied on having to edit the /etc/motioneye.conf file to include the line:
base_path /security

I had tried to ssh into the device to make the changes, however the file system is set to RO by default, so I ended up removing the microSD card and editing the files on my desktop.

That then needed to be mirrored in my apache reverse config files:
ProxyPass /security http://10.60.204.xxx
ProxyPassReverse /security http://10.60.204.xxx

And done! The new security system is accessible via ssl at: https://www.warbel.net/security/