7. Administrative Modes¶
Intrusive administration can be performed on a Pacemaker cluster without causing resource failures, recovery, and fencing, by putting the cluster or a subset of it into an administrative mode.
Pacemaker supports several administrative modes:
- Maintenance mode for the entire cluster, specific nodes, or specific resources
- Unmanaged resources
- Disabled configuration items
- Standby mode for specific nodes
Rules may be used to automatically set any of these modes for specific times or other conditions.
7.1. Maintenance Mode¶
In maintenance mode, the cluster will not start or stop resources. Recurring
monitors for affected resources will be paused, except those specifying
role
as Stopped
.
To put a specific resource into maintenance mode, set the resource’s
maintenance
meta-attribute to true
.
To put all active resources on a specific node into maintenance mode, set the
node’s maintenance
node attribute to true
. When enabled, this overrides
resource-specific maintenance mode.
Warning
Restarting Pacemaker on a node that is in single-node maintenance mode will
likely lead to undesirable effects. If maintenance
is set as a transient
attribute, it will be erased when Pacemaker is stopped, which will
immediately take the node out of maintenance mode and likely get it fenced.
If set as a permanent attribute, any resources active on the node will have
their local history erased when Pacemaker is restarted, so the cluster will
no longer consider them running on the node and thus will consider them
managed again, allowing them to be started elsewhere.
To put all resources in the cluster into maintenance mode, set the
maintenance-mode
cluster option to true
. When enabled, this overrides
node- or resource- specific maintenance mode.
Maintenance mode, at any level, overrides other administrative modes.
7.2. Unmanaged Resources¶
An unmanaged resource will not be started or stopped by the cluster. A resource may become unmanaged in several ways:
- The administrator may set the
is-managed
resource meta-attribute tofalse
(whether for a specific resource, or all resources without an explicit setting viarsc_defaults
) - Maintenance mode causes affected resources to
become unmanaged (and overrides any
is-managed
setting) - Certain types of failure cause affected resources to become unmanaged. These
include:
- Failed stop operations when the
stonith-enabled
cluster property is set tofalse
- Failure of an operation that has
on-fail
set toblock
- A resource detected as incorrectly active on more than one node when its
multiple-active
meta-attribute is set toblock
- A resource constrained by a revoked
rsc_ticket
withloss-policy
set tofreeze
- Resources with
requires
set (or defaulting) to anything other thannothing
in a partition that loses quorum when theno-quorum-policy
cluster option is set tofreeze
- Failed stop operations when the
Recurring actions are not affected by unmanaging a resource.
Warning
Manually starting an unmanaged resource on a different node is strongly
discouraged. It will at least cause the cluster to consider the resource
failed, and may require the resource’s target-role
to be set to
Stopped
then Started
in order for recovery to succeed.
7.3. Disabled Configuration¶
Some configuration elements disable particular behaviors:
- The
stonith-enabled
cluster option, when set tofalse
, disables node fencing. This is highly discouraged, as it can lead to data unavailability, loss, or corruption. - The
stop-all-resources
cluster option, when set totrue
, causes all resources to be stopped. - Certain elements support an
enabled
meta-attribute, which if set tofalse
, causes the cluster to act as if the specific element is not configured. These includeop
,alert
(since 2.1.6), andrecipient
(since 2.1.6).enabled
may be set for specificop
elements, or all operations without an explicit setting viaop_defaults
.
7.4. Standby Mode¶
When a node is put into standby, all resources will be moved away from the
node, and all recurring operations will be stopped on the node, except those
specifying role
as Stopped
(which will be newly initiated if
appropriate).
A node may be put into standby mode by setting its standby
node attribute
to true
. The attribute may be queried and set using the crm_standby
tool.
7.5. Rules¶
Rules may be used to set administrative mode options automatically according to various criteria such as date and time. See the “Rules” chapter of the Pacemaker Explained document for details.