3 ms·

Stupid question but forgive me: Whats the difference between a container and a VM?

deleted 2y ago
[deleted]
akdev1l 2y ago
A VM is a virtualized instance with virtual hardware and can therefore run its own operating system with its own kernel to interface with the virtual hardware. A container is basically a process restricted by multiple kernel namespace isolation mechanisms. It shares the same kernel with the host and does not present any “virtual hardware”.
volkadav 2y ago
high level, a vm is an entire virtual machine with its own kernel/operating system/filesystem/etc. a container is a process (and associated files/archived filesystem) with a (more or less) isolated view of the world (network/filesystem/etc.) running on top of the same kernel/os as other processes on the same machine. examples: a) vm - an entire windows install running in a window on my linux workstation so i can use tax software once a year. two kernels running at the same time. (N+1 for N VMs) b) container - a small python service, its dependencies, and various filesystem bits from alpine-minimal packaged into a file that docker/containerd/whatever can turn into the service running in a little isolated portion of my machine. no matter how many i run, one kernel. the various processes just don't see the host or other procs' files/memory/etc. via namespace trickery (unless there's a security problem, lol)
belter 2y ago
Technically, and simplifying enormously, the VM emulates the whole machine while the Container scopes the OS process. I prefer the analogy of an office building. Your VM is your whole office building and overnight maybe a whole new company can move in but still using the whole building. Your Container is a set of rules, somebody told you when arrived to the reception desk. About where is the only office in the building you can use, plus maybe some common access to shared areas once in a while, like WC and Kitchen. :-)
chadcmulligan 2y ago
This is a nice little overview https://youtu.be/eyNBf1sqdBQ https://youtu.be/eyNBf1sqdBQ

deleted 2y ago

[deleted]

A VM is a virtualized instance with virtual hardware and can therefore run its own operating system with its own kernel to interface with the virtual hardware. A container is basically a process restricted by multiple kernel namespace isolation mechanisms. It shares the same kernel with the host and does not present any “virtual hardware”.

volkadav 2y ago

high level, a vm is an entire virtual machine with its own kernel/operating system/filesystem/etc. a container is a process (and associated files/archived filesystem) with a (more or less) isolated view of the world (network/filesystem/etc.) running on top of the same kernel/os as other processes on the same machine. examples: a) vm - an entire windows install running in a window on my linux workstation so i can use tax software once a year. two kernels running at the same time. (N+1 for N VMs) b) container - a small python service, its dependencies, and various filesystem bits from alpine-minimal packaged into a file that docker/containerd/whatever can turn into the service running in a little isolated portion of my machine. no matter how many i run, one kernel. the various processes just don't see the host or other procs' files/memory/etc. via namespace trickery (unless there's a security problem, lol)

belter 2y ago

Technically, and simplifying enormously, the VM emulates the whole machine while the Container scopes the OS process. I prefer the analogy of an office building. Your VM is your whole office building and overnight maybe a whole new company can move in but still using the whole building. Your Container is a set of rules, somebody told you when arrived to the reception desk. About where is the only office in the building you can use, plus maybe some common access to shared areas once in a while, like WC and Kitchen. :-)

chadcmulligan 2y ago

This is a nice little overview https://youtu.be/eyNBf1sqdBQ https://youtu.be/eyNBf1sqdBQ