Lead Image © ping han, 123RF.com
Container Virtualization Comeback with Docker
Container Terminal
When they hear the term virtualization in an IT context, most admins almost automatically think of the standard tools such as Qemu, VMware, or Xen. What all of these solutions have in common is that they are full virtualizers that emulate entire systems. All the tools in this category impose a large overhead, even if your only need is to run individual programs in virtual environments.
Little Overhead
Container-based solutions prove that virtualization is possible with significantly less overhead. They simply lock processes into a virtual jail, avoiding the overhead of a separate operating system and contenting themselves with the resources provided by the host operating system. Nearly all operating systems have their own container implementations: FreeBSD has its jails, Virtuozzo was quite popular on Windows for a while, and, of course, Linux has containers – even multiple copies if need be: OpenVZ, LXC, and Linux VServer vie for the attention of users.
LXC (which stands for Linux Container) in particular is remarkable: Once a minor hype, this technology has now largely disappeared from the headlines and become a side issue. It definitely didn't deserve this, however. LXC containers let you perform tasks, for which virtualizing a complete operating system would definitely be over the top. The Linux Container developers will probably appreciate the way their project has made it back into the limelight: Docker is currently spreading like wildfire in the community, and it is based on LXC features.
Containers as a Service?
The developers behind Docker have basically done their homework, which the LXC developers maybe should have done. In doing so, they answered the question of why LXC has not asserted itself – probably without even being aware of it. On the one hand, the more famous full virtualizers I mentioned before
...
Buy this article as PDF
(incl. VAT)
Buy ADMIN Magazine
US / Canada
UK / Australia
Related content
-
New container solutions for Linux
Several new virtualization approaches based on Linux cgroups and namespaces technologies promise a plethora of previously unseen benefits. -
Persistent volumes for Docker containers
Equip containers with persistent storage using Docker's plugin system. -
Build and host Docker images
When facing the challenge of packaging your application in a container, take into account your needs in terms of handling and security and investigate sensible options for hosting your own registry. -
Dialing up security for Docker containers
Docker containers are a convenient way to run almost any service, but admins need to be aware of the need to address some important security issues. -
Effective debugging of Docker containers
Bugs can live in Docker containers. Read on for tips on how to debug them.
Subscribe to our ADMIN Newsletters
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Most Popular
Support Our Work
ADMIN content is made possible with support from readers like you. Please consider contributing when you've found an article to be beneficial.
