IBM SG24-5131-00 User Manual
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IBM Certification Study Guide AIX HACMP
Essentially, a snapshot saves all the ODM classes HACMP has generated
during its configuration. It does not save user customized scripts, such as
start or stop scripts for an application server. However, the location and
names of these scripts are in an HACMP ODM class, and are therefore
saved. It is very helpful to put all the customized data in one defined place, in
order to make saving these customizations easier. You can then use a
custom snapshot method to save this data as well, by including a
user-defined script in the custom snapshot.
during its configuration. It does not save user customized scripts, such as
start or stop scripts for an application server. However, the location and
names of these scripts are in an HACMP ODM class, and are therefore
saved. It is very helpful to put all the customized data in one defined place, in
order to make saving these customizations easier. You can then use a
custom snapshot method to save this data as well, by including a
user-defined script in the custom snapshot.
4.5.1 Applying a Cluster Snapshot
Applying a cluster snapshot overwrites the data in the existing HACMP for
AIX ODM classes on all nodes in the cluster with the new ODM data
contained in the snapshot. You can apply a cluster snapshot from any cluster
node. However, you have to differentiate between two possible states the
cluster could be in when applying the snapshot.
AIX ODM classes on all nodes in the cluster with the new ODM data
contained in the snapshot. You can apply a cluster snapshot from any cluster
node. However, you have to differentiate between two possible states the
cluster could be in when applying the snapshot.
If cluster services are inactive on all cluster nodes, applying the snapshot
changes the ODM data stored in the system default configuration directory
(DCD). If cluster services are active on the local node, applying a snapshot
triggers a cluster-wide dynamic reconfiguration event. In dynamic
reconfiguration, in addition to synchronizing the ODM data stored in the
DCDs on each node, HACMP for AIX replaces the current configuration data
stored in the active configuration directory (ACD) with the changed
configuration data in the DCD. The snapshot becomes the currently active
configuration.
changes the ODM data stored in the system default configuration directory
(DCD). If cluster services are active on the local node, applying a snapshot
triggers a cluster-wide dynamic reconfiguration event. In dynamic
reconfiguration, in addition to synchronizing the ODM data stored in the
DCDs on each node, HACMP for AIX replaces the current configuration data
stored in the active configuration directory (ACD) with the changed
configuration data in the DCD. The snapshot becomes the currently active
configuration.
More detailed Information about Cluster Snapshot can be found in the
HACMP for AIX, Version 4.3: Administration Guide, SC23-4279, Chapter 11
as well as in the
HACMP for AIX, Version 4.3: Administration Guide, SC23-4279, Chapter 11
as well as in the
HACMP for AIX, Version 4.3: Troubleshooting Guide,
SC23-4280.
A cluster snapshot used for dynamic reconfiguration may contain changes
to either the cluster topology OR to cluster resources, but not both. You
cannot change both the cluster topology and cluster resources in a single
dynamic reconfiguration event.
to either the cluster topology OR to cluster resources, but not both. You
cannot change both the cluster topology and cluster resources in a single
dynamic reconfiguration event.
Note
Applying a cluster snapshot may affect both AIX and HACMP for AIX ODM
objects and system files as well as user-defined files.
objects and system files as well as user-defined files.
Note