This document compares virtual machines (VMs) and containers, explaining how each technology abstracts different levels of the application stack. VMs abstract the operating system from hardware, allowing multiple operating systems to run on the same physical server. Containers further abstract applications from the operating system, enabling multiple applications to run on a single operating system. While VMs provide hardware-level isolation and are battle-tested, containers offer more efficient application packaging and portability. The document concludes that VMs are best for long-running stateful applications due to security and isolation, while containers excel at short-running stateless applications due to agility.

1. VMs and Containers – Friends or Enemies
Comparing the Abstraction Models
Simone Morellato
Director Technical Product Management
Follow me @morellatosimone

2. First, application and hardware were tightly coupled
Physical Server
App

3. Second, virtualization decoupled the operating system from the
hardware, allowing for multiple operating systems to run on the
same hardware
Physical Server
App
Virtualization abstracted
the OS from the Hardware
Operating System

4. Third, container technology decoupled the application from the
operating system, allowing for multiple applications to run on
the same operating system
Physical Server
Containers
Abstracted the App from the OS
Operating System
App

5. Today on the same physical server I can run multiple operating
systems and multiple applications
Physical Server
Windows OS Linux OS
App A App B App C App D

6. Application
Operating System
Physical
Infrastructure
How was this possible? Let’s look at the application stack

7. Application
Operating System
Physical
Infrastructure
The OS has to deal with hardware dependencies
Hardware Dependencies
Drivers
• NICs
• Storage
• Agents
• Etc.

8. Application
Operating System
Physical
Infrastructure
Virtualization took care of that
Virtualization
The hypervisor
virtualizes
the hardware limiting
the number of drivers
that you need to
install on the OS

9. Application
Operating System
Physical
Infrastructure
The OS has to deal with application dependencies
Application Dependencies
• Code
• Runtime
• System tools
• System libraries
• Settings
Virtualization

10. Application
Operating System
Physical
Infrastructure
Containers took care of that
Containers
Containers virtualize
the operating system
limiting the the number of
dependencies that you need
to install on the OS.
Virtualization

11. Application
Operating System
Physical
Infrastructure
Containers took care of that
Containers
result, you get a smaller
ht-weight OS minimizing
e hassle of updating,
tching and maintaining it.
Virtualization

12. Abstract the
OS from the
hardware
Abstract the App
From the OS
2 technologies with 2 different objectives
Allows you to run multiple applications on
the same OS
Allows you to run multiple OS on the
same hardware
Application
Operating System
Physical
Infrastructure
Containers
VMware Hypervisor
VMs
Docker

13. Application
Operating System
Physical
Infrastructure
Providing 2 different kind of benefits
V to C offers a shift away from
underutilized VMs
P to V offered a shift away from underutilized
hardware
Containers
VMware Hypervisor
VMs
Docker

14. In summary
14
VMs Containers
• Hardware level isolation
• Focused on security and
multi-tenancy
• 15 years in production,
battle tested
• OS level isolation
• Efficient packaging of
applications
• Emerging, still maturing
Great for long running
Stateful applications
Great for short running
Stateless applications

15. Containers in VMs
15
VMs Containers
• Hardware level isolation
• Focused on security and
multi-tenancy
• 15 years in production,
battle tested
• OS level isolation
• Efficient packaging of
applications
• Emerging, still maturing
Great for management
and security
Great for agility & portability
VMs
rs
Best of both worlds