software:
* Use reliable ``server'' components
-
++
NOTE: Computer components with same functionality can have varying
reliability numbers, depending on the component quality. Most vendors
sell components with higher reliability as ``server'' components -
times of about 2 minutes, so you can get no more than 99.999%
availability.
+
Requirements
------------
+You must meet the following requirements before you start with HA:
+
* at least three cluster nodes (to get reliable quorum)
* shared storage for VMs and containers
* hardware redundancy (everywhere)
+* use reliable “server” components
+
* hardware watchdog - if not available we fall back to the
linux kernel software watchdog (`softdog`)
`pve-ha-lrm`::
-The local resource manager (LRM), it controls the services running on
-the local node.
-It reads the requested states for its services from the current manager
-status file and executes the respective commands.
+The local resource manager (LRM), which controls the services running on
+the local node. It reads the requested states for its services from
+the current manager status file and executes the respective commands.
`pve-ha-crm`::
-The cluster resource manager (CRM), it controls the cluster wide
-actions of the services, processes the LRM results and includes the state
-machine which controls the state of each service.
+The cluster resource manager (CRM), which makes the cluster wide
+decisions. It sends commands to the LRM, processes the results,
+and moves resources to other nodes if something fails. The CRM also
+handles node fencing.
+
.Locks in the LRM & CRM
[NOTE]
quorum the node cannot reset the watchdog. This will trigger a reboot
after the watchdog then times out, this happens after 60 seconds.
+
Configuration
-------------
-The HA stack is well integrated in the Proxmox VE API2. So, for
-example, HA can be configured via `ha-manager` or the PVE web
-interface, which both provide an easy to use tool.
+The HA stack is well integrated into the {pve} API. So, for example,
+HA can be configured via the `ha-manager` command line interface, or
+the {pve} web interface - both interfaces provide an easy way to
+manage HA. Automation tools can use the API directly.
+
+All HA configuration files are within `/etc/pve/ha/`, so they get
+automatically distributed to the cluster nodes, and all nodes share
+the same HA configuration.
+
+
+Resources
+~~~~~~~~~
+
+The resource configuration file `/etc/pve/ha/resources.cfg` stores
+the list of resources managed by `ha-manager`. A resource configuration
+inside that list look like this:
+
+----
+<type>:<name>
+ <property> <value>
+ ...
+----
+
+It starts with a resource type followed by a resource specific name,
+separated with colon. Together this forms the HA resource ID, which is
+used by all `ha-manager` commands to uniquely identify a resource
+(example: `vm:100` or `ct:101`). The next lines contain additional
+properties:
+
+include::ha-resources-opts.adoc[]
+
+
+Groups
+~~~~~~
+
+The HA group configuration file `/etc/pve/ha/groups.cfg` is used to
+define groups of cluster nodes. A resource can be restricted to run
+only on the members of such group. A group configuration look like
+this:
+
+----
+group: <group>
+ nodes <node_list>
+ <property> <value>
+ ...
+----
+
+include::ha-groups-opts.adoc[]
-The resource configuration file can be located at
-`/etc/pve/ha/resources.cfg` and the group configuration file at
-`/etc/pve/ha/groups.cfg`. Use the provided tools to make changes,
-there shouldn't be any need to edit them manually.
Node Power Status
-----------------
projects / pve-docs.git / blobdiff