As a (part time) qemu developer, why do you think VirtualBox is preferable, eg. what are the feature gaps that qemu doesn't provide, or what could qemu do better? (And by "qemu" I include the broader free ecosystem like virt-install, virt-manager, etc)
I think part of it is that it is a complex ecosystem to understand. What is qemu, what is KVM, what is virt-manager, how does it all fit together. It is actually not hard to use but it is confusing to understand at first, what is used for what etc.
Either you are into it, and you know, or the need to create a VM has just arose and you want to quickly do it. In the later case from my Fedora 31 system I search for "Vir"(tual), it tells me about "Boxes", I open it... and it can't be simpler. I end up with a Virtual machine with QEmu/KVM without ever having to know what QEmu/KVM is, as far as random user knows "yesterday I had problems with VirtualBox kernel modules, so I created a VM with Boxes".
Pointy-clicky GUI for people who don't live the #VMLife and just occasionally want to throw some graphical OS in a VM and mess around in it for a few minutes, without having to read any man pages. I know Qemu has GUI interfaces available, but the key there is that it's plural, as in there's more than one. VBox is just the one, entire thing, all one part, no thinking required or choices to make, just start it and go.
(for the record I've done some Linux KVM/Libvirt management of VMs on servers so I'm not entirely without a clue, but VBox runs everywhere I am and is my go-to for low value messing about, especially now that all that stuff has long ago fallen out of my head. If I had to do anything serious or non-interactive I'd not be looking at VirtualBox for it.)
I used VirtualBox and the last time I installed Linux I gave Gnome Boxes a try to run a Windows VM every once in a while and I haven’t felt the need to go back to VirtualBox.
Shared folder support is lacking. I have to use NFS to share any folders in VMs when using QEMU and virt-manager. Which isn’t necessarily bad but it’s an extra config step. The built in method (which uses Plan9 I think?) is a huge headache in terms of setting up permissions. Out of the box it never works right and there isn’t any straightforward documentation on getting it configured properly.
VirtualBox, VMware and Parallels all offer much better shared folder options that are built in.
As someone who moved from vbox to QEMU (and is happy about it)...
Virtualbox is one product, one package. That’s easy to sell, install, understand and google when you need help.
Virt-manager, libvirt, QEMU and kvm... Takes more time to understand, and googling it when you need help requires you to partially understand it. Kinda chicken and the egg.
Also with Vbox I get the VMs desktop scaling to my Vbox-window, as opposed to the other way around, which I get with QEMU. That still annoys me slightly.
With VirtualBox, Windows guests can be configured to use 3d acceleration with just installing guest additions. With qemu (virt-manager), it's a major pain in the ass. I spent a couple of hours trying to figure it out, and it got me nowhere. So thanks for nothing. I prefer solutions that work, and currently it's VirtualBox.
I'd like to see some improvements to virt-manager. And has zfs storage pools actually been implemented yet? Last time I checked it still doesn't work. I can however create zvols and use those, which is fine for me.
Other than these somewhat small things qemu is the fantastic, much appreciation for your work!
Virt-manager is basically the same UI as VirtualBox with the same dead-easy, wizard-based VM setup. Plus the virt-manager running on my desktop can simultaneously drive KVM running locally and on many different servers.
