Difference between Virtual Machine and Docker

Docker containers wrap a piece of software in a complete filesystem that contains everything needed to run: code, runtime, system tools, system libraries – anything that can be installed on a server. This guarantees that the software will always run the same, regardless of its environment.

This illustration Source: https://www.docker.com/what-docker shows quite well how it is different from normal Virtual Machine (OK, Hypervisor can be installed on bare metal/infrastructure so but the illustration does give an idea).


A full virtualized system gets its own set of resources allocated to it, and does minimal sharing. You get more isolation, but it is much heavier (requires more resources). With docker you get less isolation, but the containers are lightweight (require fewer resources). So you could easily run thousands of containers on a host, and it won’t even blink.

There are pros and cons for each type of virtualized system. If you want full isolation with guaranteed resources, a full VM is the way to go. If you just want to isolate processes from each other and want to run a ton of them on a reasonably sized host, then Docker is your friend.

VMWare Fusion Keys Reference

I just recently bought new work laptop and setup Windows 7 on it. One thing that takes time to get used to is differences in keyboard shortcuts. I have put here some of the basic commands mainly for my own reference so I wont forget.


Macintosh / Fusion
To send Ctrl+Alt+Del to a virtual machine:
  • From the Fusion menu, click Virtual Machine > Send > Crtl+Alt+Delete.
  • If you are using an external PC keyboard, press Ctrl-Alt-Delete.
  • On a full-sized Macintosh keyboard, press Control-Option-|X>. The |X> (Forward Delete) key is below the help key.
  • On a Macintosh laptop keyboard, press Fn-Ctrl-Option-Delete.
The Delete key on an Apple keyboard is actually the backspace key to all other operating systems. To send the PC Delete key to a virtual machine:
  • From the Fusion menu, go to Virtual Machine > Send Key > (Forward Delete)
  • On a MacBook or MacBook Pro keyboard, press Fn-Delete.
  • On a full-sized keyboard, press |X>. The |X> (Forward Delete) key is below the Help key.
To send the Insert key to a virtual machine:
  • On a full-sized Mac keyboard, press the Help key.
  • On older MacBook or MacBook Pro keyboards, press Fn-M. Newer MacBook models do not support Fn-M, and mapping the Insert key (to any convenient key combination chosen by the user) can be achieved in Fusion’s menu bar under VMware Fusion > Preferences > Keyboard & Mouse > Key Mapping.
Print Screen
To send the Print Screen key to a virtual machine, press F13 on a full-sized Mac keyboard.
To send the Alt-Gr key to virtual machine:
  • Press the right Option key on a full-sized Mac keyboard.
  • On European MacBook and MacBook Pro keyboards, press the Enter key next to the right Command key.
  • This is overridden when Num Lock is used for numeric keypad support.
  • To disable this Alt-Gr mapping, open the file:

    ~/Library/Preferences/VMware Fusion/preferences in a text editor and the line: pref.mapISONumpadEnterToAltGrEnabled = “FALSE”

Selecting multiple list items
  • Press and hold Ctrl-Option, then click the multiple items.
  • Disable the mouse shortcut for the secondary button (see beginning of Resolution, above), and use Ctrl+click as you would in a regular Windows environment.
Num Lock
To send the Num Lock key to a virtual machine (allowing the use of the numeric keypad), press Clear on a full-sized Mac keyboard.
Function keys
  • Press fn + the desired function key.
  • To make the Mac function keys act like regular function keys, and trigger the special functions with fn + the function key instead, go to Apple menu > System Preferences > Keyboard (or Keyboard & Mouse > Keyboard), and select Use all F1, F2, etc. keys as standard function keys.

For all keyboard shortcuts, not necessarily those pertaining to Fusion, see Apple’s Knowledge base article Mac OS X keyboard shortcuts.