virtualbox.org

Hello all,

I'm using Virtualbox to achieve several parallel terminal desktops to work with VPN's which are completely cutting communication when connected. Host machine is a 4 core Intel Xeon E3-1245v2 with HT and 64GB RAM running on Ubuntu Server 16.04.2 LTS x86_64. Currently there are 11 Windows 7 guest VM running there with 2 CPU / 4GB RAM assigned. Their main use is a VPN client to connect to external networks and use browser or dedicated applications. All 11 machines are running but max 4 is used at once. I'm always connecting to these machines via VRDP. The problem is performance. Sometimes VM are almost hanging when either guests and host machine is not very loaded. How can I check whats wrong?

Regards,
Pawel

Eleven Windows 7 guests with 2 cores each on a four core host, sounds like extreme over-commit.
Use various test programs on the host to validate resources and see what is causing the slow performance just like on metal. I doubt this is something caused by VirtualBox since it is doing its intended purpose and running a stand alone OS on the host.

You may also be interested in the following CPU Cores versus threads