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Docker vs VMware

(Issac) #1

Hi All,

What is the major difference between docker vs vmware.

(Dockertiger) #2

docker share kernel with host.

(Kylesoskin) #3

Docker does not have the overhead of a hypervisor. This makes better use of your hardware. However, since there is no hypervisor for docker you have an increased chance of containers effecting each other. Basically with docker, you get performance gain, at the expense of isolation.

So for example say I have two identical host, one running 10 docker containers and one running 10 vms. If I pegged one container, it could slow the performance of the other 9. With 10 vms, if I pegged one, that is less likely.

With the same example, say ran all docker containers at 100% and all vms at 100%, the docker containers would do more ‘work’ in the same amount of time, due to not having to go through a hypervisor.

Docker also allows much quicker start times. For example I could start 100 containers all ready to go and do work in subsecond time. However starting the same amount of vms would take forever because vms need to boot a full OS, whereas docker containers kinda share the OS of the host, and overlay on top of them.

(Yogeek) #4

I would suggest reading this great article that explains clearly why containers are not VMs :

(Paulskinnerac) #5

I use docker at work as I can build a docker image of my app, deploy it to staging, test it, then deploy an exact copy to production.

Sure we could use a tool like Ansible or Chef. Those tools will run a script I create to ensure my staging and production environments are identical. But the docker is quick to build and it deploys to my AWS hosts in 30 seconds.

Its great on Amazon Web Services as I can create test copies of our software and the open source apps it depends on (eg rabbitmq) in seconds.