Docker vs Virtual Machine

Main difference between Docker and VM

• Size
  • VM : large size

    To execute program, VM needs to have GuestOS which is very large size

  • Docker : small size

    Docker needs only bin/lib files which is compact size

• Speed
  • VM : slow

    For example, when I/O occurs, VM needs to transfer the I/O from the GuestOS into HostOS, and transform to HostOS I/O driver

  • Docker : fast

    Docker container share its kernel with host OS, so doesn’t need to transform it

• lifecycle(Portability)
  • VM : complicate

    for example, just in case you want to upgrade the version of your program. With VM, you need to pull from registry, update all configuration files, reset environments, etc. So it is very hard to change or update your program

  • Docker : easy

    Docker can simplify this process. Download image, run it!

Thus, with Docker, you can easily scale out your app. And this is a basic skill that lead you to make your service with Micro Architecture Service!