Daemons
The Toolstack consists of a set of co-operating daemons:
- xapi
- manages clusters of hosts, co-ordinating access to shared storage and networking.
- xenopsd
- a low-level “domain manager” which takes care of creating, suspending, resuming, migrating, rebooting domains by interacting with Xen via libxc and libxl.
- xcp-rrdd
- a performance counter monitoring daemon which aggregates “datasources” defined
via a plugin API and records history for each. There are various rrdd-plugin daemons:
- xcp-rrdd-gpumon
- xcp-rrdd-iostat
- xcp-rrdd-squeezed
- xcp-rrdd-xenpm
- xcp-networkd
- a host network manager which takes care of configuring interfaces, bridges and OpenVSwitch instances
- squeezed
- a daemon in charge of VM memory management
- xapi-storage-script
- for storage manipulation over SMAPIv3
- message-switch
- exchanges messages between the daemons on a host
- xapi-guard
- forwards uefi and vtpm persistence calls from domains to xapi
- v6d
- controls which features are enabled.
- forkexecd
- a helper daemon that assists the above daemons with executing binaries and scripts
- xhad
- The High-Availability daemon
- perfmon
- a daemon which monitors performance counters and sends “alerts” if values exceed some pre-defined threshold
- mpathalert
- a daemon which monitors “storage paths” and sends “alerts” if paths fail and need repair
- wsproxy
- handles access to VM consoles