Paravirtualization is a virtualization technique that presents a software interface to virtual machines that is similar but not identical to that of the underlying hardware. This requires operating systems to be explicitly ported to run on top of the virtual machine monitor (VMM), which the owner of exclusive rights in a proprietary operating system may decline to allow for strategic purposes, but may enable the VMM itself to be simpler and for the virtual machines that run on it to achieve higher performance.
It does not require complete emulation of hardware devices. Paravirtual mode uses an API to interact with the host virtualization platform.
To determine if the server has PAE support, enter:
# grep pae /proc/cpuinfo
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm up
If the system has PAE support, it can run a para-virtualized guest using XEN or other tools.
If there is no output at all, then the server is not capable of running para-virtualized guest operating system using XEN or other tools.
Updated for accuracy!