[p0w3n3d]

could you please tell what's the difference between VirtualBox and VMWare ESX? I mean what's the VirtualBox lacking as compared to ESX? I've never used an enterprise VMWare so I can't imagine what's different there? Especially if Hyper-V is proposed as an alternative...

--- EDIT ---

I've made some research and now understand that Hyper-V runs alongside the Windows Server (i.e. it is not an in-windows app). Therefore it would be hard to achieve the ESX performance close to ESX or Hyper-V even when deploying on linux. Or wouldn't it? Maybe considering a partition as disk for virtualbox? Idle Linux overhead isn't this much, is it?

[Macha]

Parallels and virtualbox are designed for the end user ad hoc running a few VMs on their client system. The VMWare equivalent was VmWare Workstation, not ESX. ESX, Proxmox etc. are about orchestrating fleets of VMs running on clusters of hardware

[zamadatix]

It's not really about performance. Imagine comparing AirDrop to a SAN on the basis both provide file sharing functionality. The topic wouldn't be performance, it'd be how they have entirely different use case goals that just happen to both end up using file sharing as one part in achieving that goal.

In the case of ESXi it's about the clustering, filesystem/network virtualization, management and orchestration for hundreds of servers, disaster recovery, enterprise security/software integrations, and so on. That VirtualBox requires a client OS is just a footnote in the comparison of functionality.