KVM Virtual Machines
Last updated: October 26th 2022
Webdock now supports KVM Virtual Machines as a VPS virtualization option. These VPS instances are what you might call "classic" VPS servers and have the primary strength that they are fully virtualized and thus are essentially 100% compatible with all software and can do some things our Webdock LXD VPS servers cannot.
KVM Virtual Machines are only available on Ryzen
... For now
Our KVM instances are a new feature to Webdock and we are still gaining experience with this virtualization type. When we went live with KVM instances we discovered that our existing Intel Xeon environments were, for legacy reasons, configured in slightly different ways and had differing OS, Kernel, and Hypervisor versions running. This caused some rather fatal problems and we decided to block KVM provisioning on our Xeon machines until we can deploy new capacity to our data centers which will then be dedicated to KVM hosting. On the other hand, our Ryzen systems were all identical in configuration and software versions and much better suited for KVM virtualization.
KVM Virtual Machines carry a small surcharge
KVM Virtual Machines put more continuous load on our infrastructure with regard to CPU utilization and higher bandwidth and disk use for our snapshot/backup systems as the images are simply larger.
KVM Virtual Machines cannot be downgraded
They can only be upgraded as the disk drive space allocation cannot be shrunk. It is simply impossible to shrink a block device once it has been expanded to a certain size. If you want to downgrade a KVM server in the future, you will need to create a new server and manually transfer your data.
Live Statistics / Usage will not be visible in the Webdock Dashboard for KVM instances
As KVM instances are much more isolated (i.e. fully virtualized) we cannot read live usage statistics such as current CPU and bandwidth use as we can with our Webdock LXD VPS instances. If you want to monitor usage live, you can SSH in to your KVM and install/run "htop" or install something like Netdata on your VPS.
LXD-Agent is Required to run in your KVM VPS
Once you spin up a KVM VPS server with us, you may notice a small daemon running in the background called "lxd-agent". This is a piece of software which enables us to do all the cool things we can do in Webdock - such as install software, run commands in your server to add shell users, pull utilization metrics from your VPS for our statistics and much more. LXD-Agent is so important to the well-being and operation of your VPS in fact, that we have decided to add this as a strict requirement to our Terms and Conditions.
You cannot mix and match LXD and KVM instances
It is unfortunately not possible to spin up a KVM instance from an existing Webdock LXD VPS snapshot image, or vice-versa, as the two modes of virtualization are mutually incompatible.