Cloud Backup stew in Docker container? Check – Asigra

Quick as a flash, Asigra has added Docker container support to its Cloud Backup product. Traditional virtualised servers have applications running in a virtual machine (VM or virtual server) with a guest operating system. Multiple VMs have multiple copies of guest VMs, which is wasteful of server memory and processor resources …

[Lusty]

Wasteful?

It's not wasting system resources if the "legacy" VM offers many more useful features than a container. There is nothing legacy about a virtual machine, it simply serves a different purpose and is useful to a different set of people. I have nothing against Docker, but this text reads like propaganda rather than useful information. I especially love the way they inserted a host OS into a virtualisation stack to make it look less efficient - the host OS doesn't sit there in a proper hypervisor setup. I'm not saying docker isn't lighter, but they shouldn't need to bodge a diagram to say that.

[TheMusicGuy]

Diagram wrong

It seems that the diagram is wrong to me - the hypervisor sits underneath the host OS in the VMware scenario, not the other way round. And if you are running the same OS, much of it is shared between VMs via Page Sharing. The overhead is not as great as that picture is painting......

[Graham 24]

Re: Diagram wrong

It looks to me like the diagram on the left is using a type 2 hypervisor (i.e. essentially an application running under the host OS). Since a type 2 hypervisor is not as efficient as a type 1 (i.e. VMware), that's what I'd do if I wanted to make the benchmark difference between VMs and containers as large as possible.

It's not relevant to most real world situations, but hey, this is marketing we're talking about.