June 19, 2024

Ubuntu Server in a Virtual Machine Host

If you run a physical server, virtualization could help make managing Ubuntu server easier from another computer. Doing so would enable you to save computing resources by not needing a secondary OS which might go unused.

Ubuntu servers feature support for KVM, a type-1 hypervisor which transforms underlying physical systems into virtual machines. You must enable virtualization in your BIOS prior to installing KVM.

Hardware Compatibility

Ubuntu Server was specifically created for use on servers that provide multiple services, so it does not require the same hardware as its desktop version of linux counterparts.

Memory is of paramount importance to virtual machines (VMs). It will determine their smooth operation and power.


At least 512MB of RAM should be assigned to each virtual machine (VM), in order to prevent performance issues with it.

VirtualBox VM settings offer various configuration options to set up hardware that will be utilized by the virtual machine (VM). These include:

Software Compatibility

The Virtual Machine installation will prompt you to erase the disk. Instead, select Ubuntu installation and restart once done; once rebooted you may see another prompt asking you to take action such as taking off CD or DVD drives – do nothing!

Virtual machines (VMs) can be set to operate in either bridged or NAT mode to expose them directly to the network or hide them behind the host machine in a NAT manner. When operating in bridged mode, be sure to install virt-viewer so you can remotely access your VM.

Ubuntu Server’s virt-manager GUI can be used to easily create and manage virtual machines (VMs). It supports basic virtualization features, including live/online migration and cloning running VMs; additionally it features a powerful CLI for advanced users. KVM, an open-source Linux kernel-based hypervisor that’s fast and lean – perfect for use with 32- and 64-bit guests, including those running x64 OSes – provides excellent performance as it is PAE compliant (enabling 32-bit CPUs access more than 4 GB memory).



Staying current with operating system updates is key to protecting against security vulnerabilities used by attackers to compromise servers. Be sure to install patches addressing security issues for other software installed on your machine in addition to updating OS and applying updates as soon as they become available.

Passwords are another essential aspect of protecting a virtual machine (VM). Be sure to create a strong password by mixing capital letters, lower case letters, numbers and special characters into it – do not share this password with anyone!

CVE-2018-12126 and CVE-2018-12130 both feature mitigations that prevent leaks by clearing buffers upon entering or leaving C state, making sure your host OS has updated CPU microcode. It is also recommended that hosts affected by these CPU bugs disable hyperthreading (HT), which may have performance impact depending on their workload – to do this safely contact your motherboard/system firmware manufacturer to obtain updates on this matter.


If performance is low, follow the troubleshooting steps outlined by VMware to identify and isolate the source of your issue and find its resolution. Be wary of antivirus programs scanning virtual disk files as this can severely degrade VM performance.

Check that the host operating system is not using too many CPU (CPU core) resources and that the amount of memory allocated to each VM does not overcommit host memory.

Maximum allocation can be set when creating the virtual machine, but can also be increased later by selecting it in the Virtual Machines interface and clicking edit under Overview section.

VMware Tools should be installed on every VM for improved performance. They offer various utilities to improve graphic performance and synchronize mouse movements; additionally, installing them reduces CPU load.