Learning how to do things is difficult, and I tend to forget it. I'll take a note about them, and as I write them it will help me to make the global vision
When dealing with virtual machines, the QCOW2 disk format is often praised for its space-saving capabilities. By design, it stores only the differences from the base image, making it a smart choice for snapshots and layered storage. However, if you ve used QCOW2 disks for any length of time, you might have noticed something counterintuitive: the Continue reading How to reclaim the free storage…
Recently I had the need to create a Windows 11 VM for KVM. I created it as explained in my previous post, and I noticed that Windows 11 did not want to install in a legacy boot-based VM (i.e. no EFI). The effect was that it allowed going through the first steps of the installation, Continue reading How to install Windows 11 in a VM with legacy boot (i.e. in a non EFI machine)
In one project, we have the need to test an application for the different platforms in which it is available. One of them is Windows, and to test the software, we spawn a Virtual Machine in which the application is installed, tested, etc. The backend for the VMs is OpenStack and KVM, so this time Continue reading How to create Windows 10 or Windows 11 Virtual Machines in OpenStack (using KVM)
In the last few months, I had the need of installing Tensorflow on machines that had NVIDIA GPUs. The users also wanted to use Jupyter. The process is very straightforward, consisting of installing CUDA, CUDNN, TensorFlow and Jupyter. But the problem is that installing all these things involve a lot of time (searching for the Continue reading How to use Tensorflow and Jupyter in a machine with an…
In some situation I needed to resize OpenStack instances (i.e. change the flavor to give more resources to the instance). I thought that OpenStack had it enabled in the default installation, but this feature will not work in an out-of-the-box deployment, if you follow the tutorials that you find in the Internet. If you only Continue reading How to enable OpenStack instance resizing and migration
I have written several posts on installing OpenStack Rocky from scratch. They all have the tag #openstack. In the previous posts we… Installed OpenStack Rocky (part 1, part 2, and part 3). Installed the Horizon Dashboard and upgraded noVNC (install horizon). Installed Cinder and integrated it with Glance (in this post). And now that I have a Dell Continue reading How to use a Dell PS Equallogic as…
I have written several posts on installing OpenStack Rocky from scratch. They all have the tag #openstack. In the previous posts we Installed OpenStack Rocky (part 1, part 2, and part 3). Installed the Horizon Dashboard and upgraded noVNC (install horizon). So we have a working installation of the basic services (keystone, glance, neutron, compute, Continue reading How to install Cinder in…
I had the recent need for adding a disk to an existing installation of Ubuntu, to make the / folder bigger. In such a case, I have two possibilities: to move my whole system to a new bigger disk (and e.g. dispose of the original disk) or to convert my disk to an LVM volume Continue reading How to move from a linear disk to an LVM disk and join the two disks into an LVM-like RAID-0
Under some circumstances, we may have the need of moving a working installation of Ubuntu to another disk. The most common case is when your current disk runs out of space and you want to move it to a bigger one. But you could also want to move to an SSD disk or to create Continue reading How to move an existing installation of Ubuntu to another disk
LVM stands for Logical Volume Manager, and it provides logical volume management for Linux kernels. It enables us to manage multiple physical disks from a single manager and to create logical volumes that take profit from having multiple disks (e.g. RAID, thin provisioning, volumes that span across disks, etc.). I needed using LVM multiple times, Continue reading How to use LVM