• Architecture
• Architecture
• High-level Features
• Disaster Recovery
• High-Availability
• Xapi Storage Migration
• Rolling Pool Upgrade
• vGPU
• Snapshots
• Backtrace support
• Xapi
• Xapi Overview
• Xapi architecture
• Host memory accounting
• Xenopsd
• Xenopsd overview
• Features
• Architecture
• Xenopsd roadmap
• Events
• Tasks
• Requirements for suspend image framing
• Suspend image framing format
• Walkthrough: Starting a VM
• Squeezed
• Squeezed overview
• Squeezed architecture
• Squeezed design

Xapi is the xapi-project host and cluster manager. Xapi is responsible for - aggregating hosts into a single entity (a "resource pool") - allocating VMs to hosts - managing shared storage - recoverying from host failure ("High-Availability") - preparing for site failure ("Disaster Recovery") - providing the XenAPI XMLRPC interface - upgrading pools - hotfixing hosts - reporting bugs etc

Principles

1. The XenAPI interface must remain backwards compatible, allowing older clients to continue working
2. Xapi delegates all Xenstore/libxc/libxl access to Xenopsd, so Xapi could be run in an unprivileged helper domain
3. Xapi delegates the low-level storage manipulation to SM plugins.