Disk space is dedicated, but the HDDs and SSDs are shared.
There is no overprovisioning
between virtual servers. In other words if there are 10 virtual servers and each has a 50GB
disk, there is at least 500GB storage available on the host.
The virtual server
most likely would share the HDD or SSD with other virtual servers. And
it is important to understand that the bigger the disk of the VDS the fewer neighbors
it will have on the same hard drive and faster it would be.
However the virtual servers are guaranteed but not locked to use just a percentage of disk time. If at any time there are no other users of the disk - a single virtual server can have 100% of disk time.
Memory is dedicated without overlapping. Each virtual server has its own chunk of physical memory.
Processor is shared but guaranteed that in 95% of time it will be available for full speed. Statistics
tell us that on average the CPU usage of virtual servers is only 9%. That includes peak hours with
usage of 100% and slow hours when usage is close to zero. This is one of the greatest
features of virtualization when you benefit so much from the CPU sharing without
losing the performance.
In real life the combined CPU usage of our host server is
never above 60% and the availability of virtual CPUs is always 100% for all virtual
servers.