Docker Notes -1

 docker-compose down --rmi -all

how do we run two OS in one machine - Using Hypervisor

OS1  | OS2

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Hypervisor

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Machine OS

Hypervisor : Virtual Box, VMVare, Hyper-v(only Windows)

Benifit creating Virtual machine

Run application in isolation

same application using different version

eg:

virtual Machine1{App1 with Node14, Mongo 4}

virtual Machine2{App2 with Node9, Mongo 3}

Problems with VMs

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Each machine needs full-blown OS (license)

Slow to start ( cause entire OS needs to start just as a normal machine)

Resource intensive ( takes certain Hardware - RAM, cpu ..)

Containers

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Allow running multiple apps in isolation(same kind of a isolation)

light weight

Use OS of the host ( share)

Start quickly ( OS already started)

need less hardware resources

so can run more containers compared to vms

docker run client - server architecture

client communicate using RESTApi

server --> docker engine

technically container is a process

basically all containers use kernal of the host

kernal - manages all applications and hardware

aw-mode is unavailable courtesy of Hyper-V. (VERR_SUPDRV_NO_RAW_MODE_HYPER_V_ROOT).

You must have experienced below error when trying to start your VM. eg: start Linux server from Oracle VM Virtual Box.
I have Orcle VM  and docker installed in the machine

OS = Windows 10

Below is the error:

Failed to open a session for the virtual machine LinOra_1.

Raw-mode is unavailable courtesy of Hyper-V. (VERR_SUPDRV_NO_RAW_MODE_HYPER_V_ROOT).

Result Code: E_FAIL (0x80004005)
Component: ConsoleWrap
Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed}


Power up failed (vrc=VERR_SUPDRV_NO_RAW_MODE_HYPER_V_ROOT


Solution:
Disable the hyper v from windows OS.

When running docker, this is enabled. So it's difficult to run docker and Oracle VM at same time.