This is how you regain disk space from OpenStack instances if you are using kvm and qcow.

If your instance used up all configured disk space once the disk file remains big. You can end up in a situation where for example the instance use only 20G...

To open a terminal quickly navigate to System → Preferences → Keyboard Shortcuts. There, click the "Run a terminal" row (It should be in the "Desktop" section) and press the keyboard shortcut you like.

If you cannot find such an entry you may nee...

Why do we migrate?

Due to a change in licensing, we cannot provide Elasticsearch versions >= 8.0.
Version 7.17.x will reach EOL status with the release of Elas...

ImageMagick has a command line tool called identify which can read image metadata:

>identify -verbose DSC00136.JPG
Image: DSC00136.JPG
  Format: JPEG (Joint Photographic Experts Group JFIF format)
  Class: DirectClass
  Geometry: 5472x3648+...

A primer on vector graphics

For rastered image formats like JPG or PNG, each pixel is basically drawn on a fixed size canvas. To display such an image in a different size (say: 1.5 times larger than original), the renderer (your Browser / GPU...

I recently noticed that better_errors allows you to to open files from within your favorite editor. However it was not so easy to get rubymine:// links to work ...

Every time you open a directory containing images, Windows creates those pesky Thumbs.db files for a minor speed-up and lots of cluttering your zip files etc.

You do want to disable them. Here is how on Windows 7:

1. Start → Run (or press Me...

There are various ways to run external commands from within Ruby, but the most powerful ones are Open3.capture3 and Open3.popen3. Since those can do almost everything you would possibly need in a clean way, I prefer to simply...