Hacker News Reader

Maybe I am missing something but the last few times I tested VMs it seemed to end up never shrinking in RAM size once it had grown, is this a real issue and if so is there any improvement coming on that front?

View on HN

You're missing the complexity of making the guest inform the host that it has fully freed this and that slab of memory and that the host may reclaim it until further notice. It's a bit more complicated than the other way around, where the guest believes it has e.g. 4 GiB of RAM available but the host doesn't allocate all of it for the guest until it tries to read/write there. A virtual machine is something entirely else than a containerized piece of software.

> Maybe I am missing something but the last few times I tested VMs ...

Tested VMs on what? For VMs are used daily and there are, what, hundreds of millions of VMs running as we speak? Billions?

Reply on news.ycombinator.com