IT大师傅106-Docker与虚拟机对比

when i first started learning docker after understanding some of the main concepts my first question was okay so what is a difference between docker and an oracle virtual box for example and the difference is quite simple i think and in this short video i'm gonna cover exactly that and i'm gonna show you the difference by explaining how dock works on an operating system level and then comparing it to how virtual machine works so let's get started in order to understand how docker works on the operating system level let's first look at how operating system is made up so operating systems have two layers operating system kernel and the applications layer so as you see in this diagram the kernel is the part that communicates with the hardware components like cpu and memory etc and the applications run on the kernel layer so they are based on the kernel uh so for example we you all know linux operating system and there are lots of distributions of linux out there there there there is bonto and dbn and there is linux meand etcetera there are hundreds of distributions they all look different so the graphical user interface is different the file systems may be different so a lot of applications that use are different because even though they use the same lenix kernel they use different or they implement different applications on top of that kernel so as you know docker and virtual machine they're both virtualization tools so the question here is what parts of the operating system they virtualize so docker virtualizes the applications layer so when you download a docker image it actually contains the applications layer of the operating system and some other applications installed on top of it and it uses the kernel of the host because it doesn't have its own kernel the virtual box or the virtual machine on the other hand has the applications layer and its own kernel so it virtualizes the complete operating system which means that when you download a virtual machine image on your host it doesn't use your post kernel it boots up its own so what does this difference between docker and virtual machine actually mean so first of all the size of docker images are much smaller because they just have to implement one layer so docker images are usually a couple of megabytes ah virtual machine images on the other hand so

·第二、是speed，so you can run and start docker containers much faster than the vms because they every time you start them.

·第三、是kernel，so you can run a virtual machine image of any operating system on any other operating system host.

·第四、是windows operating system with a kernel and some applications.

·第五、是linux based docker image on that windows host.

·第六、是linux based stocker image might not be compatible with the windows kernel.

·第七、是actually true for the windows versions below 10.

·第八、是also for the older mac versions.

·第九、是if you have seen my video how to install docker on different operating systems.

·第十、是to check whether your host can actually run docker natively.

·第十一、是basically means is the kernel compatible with the docker images.

·第十二、是that you install a technological docker toolbox.

·第十三、是abstracts away the kernel to make it possible.

·第十四、是your host to run different docker images.

·第十五、是thanks for watching the video.

·第十六、是hope it was helpful.

·第十七、是if it was don't forget to like it.

·第十八、是video series.

·第十九、是i will create a new one every week.

·第二十、是if you want to be notified whenever a new video comes out.

·第二十一、是subscribe to my channel.

·第二十二、是if you have any questions if something wasn't clear in the video.

·第二十三、是please post them in the comment section below.

·第二十四、是i will try to answer them.

·第二十五、是thank you.

·第二十六、是see you in the next video.