Virtual QMT
From Qmailtoaster
This page is under construction
What you will find here for the most part is not directly related to QMail-Toaster. While many people are bringing their systems into the 'virtual age', we haven't found any comprehensive and concise source that address what we've found to be important aspects of running a QMT host (or any host) in a virtual environment. Also, we are trying to keep the explanations and language geared towards everyone, not just the uber-techies.
Contents |
Virtualization Hardware
While specific hardware that supports virtualization is not necessarily required to use many virtualization products, a brief discussion of virtualization hardware is in order.
CPU
VMM
First generation virtualization hardware for the x86 architecture was introduced in 2006. Intel's VT-x and AMD's AMD-V implement in hardware some of the Virtual Machine Monitor functionality that was previously only implemented in software.
MMU
Second generation virtualization hardware was introduced in 2007. AMD's Rapid Virtualization Indexing (RVI, aka nested paging tables or NPT) and Intel's Extended Page Tables (EPT) provide hardware support of Memory Management Unit virtualization.
Memory
Memory utilization in a virtualized environment is significatant to performance, though it's all handled by the CPU and/or software (see MMU above). There is no special memory hardware with regards to virtualization. As usual though, the more memory the better. On the host anywise (see memory limits on guests).
Storage
Network
Paravirtualization
Virtual Machine Interface (VMI)
Virtualization Software
KVM
OpenVZ
VirtualBox
VMware
Xen
From the looks of this article, it appears that Xen doesn't have much of a future. I expect it would be wise to steer clear of Xen.
References
- Virtuatopia.com has a vast amount of virtualization references that encompass a variety of popular virtualization platforms. Their online books are good for learning and reference. They also have tutorials, problem solutions, and Quick How To Guides.
- VMware White Paper - Virtualization Overview is a little dated, but a nice overview of virtualization.
- VMware Technical Resource Center - Performance of VMware® VMI - ESX Server 3.5