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Test: does the  xen list  command show that the current system is Domain-0?

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Toolstacks (a.k.a toolkits and toolboxes)

There are several tool(stacks|kits|boxes) toolstacks available for the personal or scripted administration of Xen resources.

Primary reference: http://wiki.xen.org/wiki/Choice_of_Toolstacks

libvirt and virsh

libvirt is a library for managing KVM, OpenVZ, VMware, VirtualBox, Xen and others.  For Xen, it is the least feature-complete of all the toolstacks.

Logs in the /var/log/xen-tools/ directoryvirsh is a user/script shell to interface with libvirt.  References: http://libvirt.org/virshcmdref.html

xen-tools

xapi and xe

The most feature-complete of all the toolstacks.

xend and xm

Deprecated since Xen 4.1 but the default in Xen 4.1 as packaged for Debian.  Will be removed from Xen 4.2.

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Designed to be command line compatible with xend.  TODO: does it have an xm command?

Toolstack library

Libxenlight (libxl)

The strategic Xen toolstack library, designed to hide xenstore, libxenctrl, and libxenguest from higher levels.

Configuration

DomU*

Networking

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• Domain  a Xen VM.
• dom0  The Xen domain/VM used a) to control the hypervisor b) as the primary interface to the hardware.
• domu*  Unprivileged Xen domains/VMs
• Enlightened guest  An OS designed/modified for use in a domain/VM.
  
• Full virtualisation  A domain/VM providing full emulation of physical hardware.  The OS can be the same as runs on real hardware.
• Guest domain  Same as domu*.
• Hardware Virtual Machine (HVM)  Same as full virtualisation.
• Hypervisor a software system that allows the execution of multiple virtual guest operating systems simultaneously on a single physical machine. Xen's hypervisor is Type 1 or “bare-metal”, meaning it runs on the physical machine as opposed to within an operating system.
• HVM  Hardware Virtual Machine.
• Para-virtualization  uses modified guest operating systems a.k.a. enlightened guests. They don’t require virtual hardware devices, instead they make special calls to the hypervisor that allow them to access CPUs, storage and network resources.  Better performance that full virtualisation.
• PV  para-virtualisation.
• Virtual Machine Monitor (VMM)  Same as hypervisor.
• Xen Store  A database of information shared by the hypervisor, the kernels, the drivers and the xen daemon.  The memory for Xen Store is provided by Dom0.  In Dom0 (and in enlightened guests?) it can be accessed via /proc/xen/xenbus/

Technical

TODO; move Xen notes from the Online.net server page to here.

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Very little information found on the 'net about Xen architecture.  This diagram is from http://libvirt.org/architecture.html

TODO: mine http://wiki.xen.org/wiki/XenIntro for more information.

Debian packages

libxen-4.1

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xen-linux-system-amd64

xen-system-amd64

xen-tools

Logs in the /var/log/xen-tools/ directory.

xen-utils-4.1

xen-utils-common

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