VMware’s Workstation Player checks how much swap space is available before starting up any virtual machine. If the host’s available swap space isn’t at lest 50% of the VM’s memory it spits out a warning: VMWare Workstation Player showing error message due to too little swap being available Unfortunately the GUI does not offer an option to change this behavior… Read more »
On Linux qemu-nbd can be used to access disk images in different formats as if they were block devices. For example, to mount a VHD file run To unmount and disconnect the nbd device run
Currently the Fedora projects provides cloud images as qcow2 and raw disk files. Microsoft’s Azure however only supports VHD files. Fortunately qemu-img can convert between those formats: Note that the subformat options fixed and force_size are required for Azure to be able to use the disk image since Azure only supports fixed sized disks.
Thankfully the Fedora Project provides cloud images that can be directly used or easily modified to run on almost any cloud environment. Though sometimes, it can be handy to build your own image.
Usually Linux distributions with a long life cycle like RHEL (or its free derivative CentOS), Debian or SLES are the way to go for virtual machines in a cloud environment. But sometimes you need to be a little bit closer to upstream. Maybe because your applications relies on newer version of some packages that are not (easily) available on distributions… Read more »
For some reason, VMWare decided to blacklist some graphics drivers for their VMware Workstation Player. That includes the Mesa DRI drivers for most Intel IGPs, which results in unbearably slow graphic performance and potentially error messages such as “Hardware graphics acceleration is not available” or “No 3D support is available from the host” when starting a virtual machine To enable… Read more »
The Arduino IDE is great for beginners: It makes it really easy to write simple programs without having to care about compiler options, include paths, language standards or how to actually flash firmware onto the microcontroller. It even comes with a built-in serial monitor which can be a great tool for debugging. Inevitably, as people dive deeper into the world… Read more »
These days mainboards usually come with some sort of wizbang tool that allow the user to update the BIOS from a USB drive or straight via network. Except, of course, that one single mainboard that absolutely needs a new BIOS version on a late Friday afternoon. And obviously the manufacturer only provides a flash tool for DOS and the mainboard… Read more »
Migrating a virtual machine from one host to another is usually no big deal if both hosts run the same VMM. But what if one wants to move a VM from a host running a different hypervisor than the target host? In the case of moving a VM from KVM to ESXi that’s just not (easily) possible. However, one can… Read more »
The achievable speed of copying a file with OpenSSH (e.g. with scp) will depend on quite a few different factors such as CPU speed, CPU architecture, Network throughput, OpenSSH implementation, OS, hard drive speed, etc. But how much of a difference does choosing a different cipher algorithm make? And what’s the fastest OpenSSH cipher algorithm? Turns out, there’s no simple… Read more »