|
|
@@ -62,6 +62,28 @@ be done to get it running.
|
|
|
|
|
|
*Also known as : docker-compose, fig*
|
|
|
|
|
|
+## copy-on-write
|
|
|
+
|
|
|
+Docker uses a
|
|
|
+[copy-on-write](https://docs.docker.com/engine/userguide/storagedriver/imagesandcontainers/#/the-copy-on-write-strategy)
|
|
|
+technique and a [union file system](#union-file-system) for both images and
|
|
|
+containers to optimize resources and speed performance. Multiple copies of an
|
|
|
+entity share the same instance and each one makes only specific changes to its
|
|
|
+unique layer.
|
|
|
+
|
|
|
+Multiple containers can share access to the same image, and make
|
|
|
+container-specific changes on a writable layer which is deleted when
|
|
|
+the container is removed. This speeds up container start times and performance.
|
|
|
+
|
|
|
+Images are essentially layers of filesystems typically predicated on a base
|
|
|
+image under a writable layer, and built up with layers of differences from the
|
|
|
+base image. This minimizes the footprint of the image and enables shared
|
|
|
+development.
|
|
|
+
|
|
|
+For more about copy-on-write in the context of Docker, see [Understand images,
|
|
|
+containers, and storage
|
|
|
+drivers](https://docs.docker.com/engine/userguide/storagedriver/imagesandcontainers/).
|
|
|
+
|
|
|
## container
|
|
|
|
|
|
A container is a runtime instance of a [docker image](#image).
|
|
|
@@ -100,19 +122,21 @@ lightweight Docker development environment designed specifically for the Mac. A
|
|
|
native Mac application, Docker for Mac uses the macOS Hypervisor framework,
|
|
|
networking, and filesystem. It's the best solution if you want to build, debug,
|
|
|
test, package, and ship Dockerized applications on a Mac. Docker for Mac
|
|
|
-supersedes [Docker Toolbox](#toolbox) as state-of-the-art Docker for macOS.
|
|
|
+supersedes [Docker Toolbox](#toolbox) as state-of-the-art Docker on macOS.
|
|
|
+
|
|
|
|
|
|
## Docker for Windows
|
|
|
|
|
|
[Docker for Windows](https://docs.docker.com/docker-for-windows/) is an
|
|
|
easy-to-install, lightweight Docker development environment designed
|
|
|
-specifically for Windows systems. Docker for Windows uses Microsoft Hyper-V, and
|
|
|
-runs as a native Windows app. It works with Windows Server 2016, and gives you
|
|
|
-the ability to set up and run Windows containers as well as the standard Linux
|
|
|
-containers (with an option to switch between the two). Docker for Windows is the
|
|
|
-best solution if you want to build, debug, test, package, and ship Dockerized
|
|
|
-applications on Windows machines. It supersedes [Docker Toolbox](#toolbox) as
|
|
|
-state-of-the-art Docker on Windows.
|
|
|
+specifically for Windows 10 systems that support Microsoft Hyper-V
|
|
|
+(Professional, Enterprise and Education). Docker for Windows uses Hyper-V for
|
|
|
+virtualization, and runs as a native Windows app. It works with Windows Server
|
|
|
+2016, and gives you the ability to set up and run Windows containers as well as
|
|
|
+the standard Linux containers, with an option to switch between the two. Docker
|
|
|
+for Windows is the best solution if you want to build, debug, test, package, and
|
|
|
+ship Dockerized applications from Windows machines. Docker for Windows
|
|
|
+supersedes [Docker Toolbox](#toolbox) as state-of-the-art Docker on Windows.
|
|
|
|
|
|
## Docker Hub
|
|
|
|
|
|
@@ -296,13 +320,25 @@ For Windows 10 systems that support Microsoft Hyper-V (Professional, Enterprise
|
|
|
and Education), [Docker for
|
|
|
Windows](https://docs.docker.com/docker-for-windows/) is the better solution.
|
|
|
|
|
|
-
|
|
|
## Union file system
|
|
|
|
|
|
-Union file systems, or UnionFS, are file systems that operate by creating
|
|
|
-layers, making them very lightweight and fast. Docker uses union file systems to
|
|
|
-provide the building blocks for containers.
|
|
|
-
|
|
|
+Union file systems implement a [union
|
|
|
+mount](https://en.wikipedia.org/wiki/Union_mount) and operate by creating
|
|
|
+layers. Docker uses union file systems in conjunction with
|
|
|
+[copy-on-write](#copy-on-write) techniques to provide the building blocks for
|
|
|
+containers, making them very lightweight and fast.
|
|
|
+
|
|
|
+For more on Docker and union file systems, see [Docker and AUFS in
|
|
|
+practice](https://docs.docker.com/engine/userguide/storagedriver/aufs-driver/),
|
|
|
+[Docker and Btrfs in
|
|
|
+practice](https://docs.docker.com/engine/userguide/storagedriver/btrfs-driver/),
|
|
|
+and [Docker and OverlayFS in
|
|
|
+practice](https://docs.docker.com/engine/userguide/storagedriver/overlayfs-driver/)
|
|
|
+
|
|
|
+Example implementations of union file systems are
|
|
|
+[UnionFS](https://en.wikipedia.org/wiki/UnionFS),
|
|
|
+[AUFS](https://en.wikipedia.org/wiki/Aufs), and
|
|
|
+[Btrfs](https://btrfs.wiki.kernel.org/index.php/Main_Page).
|
|
|
|
|
|
## virtual machine
|
|
|
|
Sebastiaan van Stijn