IBM AIX HACMP, Руководство пользователя по оборудованию

Страница: 187 / 240

Cluster Management and Administration
169
• If the Cluster Manager is active on the local node, synchronization triggers
a cluster-wide, dynamic reconfiguration event. In dynamic reconfiguration,
the configuration data stored in the DCD is updated on each cluster node,
and, in addition, the new ODM data replaces the ODM data stored in the
ACD (Active Configuration Directory) on each cluster node. The cluster
daemons are refreshed and the new configuration becomes the active
configuration. In the HACMP for AIX log file, reconfig_resource_release,
reconfig_resource_acquire, and reconfig_resource_complete events mark
the progress of the dynamic reconfiguration.
• If the Cluster Manager is active on some cluster nodes but not on the local
node, the synchronization is aborted.
8.5.3 DARE Resource Migration Utility
The HACMP for AIX software provides a Dynamic Reconfiguration (DARE)
Resource Migration utility that allows for improved cluster management by
allowing a system administrator to alter the placement of resource groups
(along with their resources—IP addresses, applications, and disks) to specific
cluster nodes using the
cldare
command. The command lets you move the
ownership of a series of resource groups to a specific node in that resource
group’s node list, as long as the requested arrangement is not incompatible
with the current resource group configuration. It also lets you disable
resource groups, preventing them from being acquired during a failover or
reintegration.
Dynamic resource group movement essentially lets a system administrator
better use hardware resources within the cluster, forcing resource traffic onto
one or more high-powered or better-connected nodes without having to shut
down HACMP on the node from which the resource group is moved. Dynamic
resource group movement also lets you perform selective maintenance
without rebooting the cluster or disturbing operational nodes.
Using the DARE Resource Migration utility does not affect other resource
groups that might currently be owned by that node. The node that currently
owns the resource group will release it as it would during a “graceful
shutdown with takeover”, and the node to which the resource group is being
moved will acquire the resource group as it would during a node failover.
The following section covers the types and location keywords used in DARE
resource migrations, and also how to use the
cldare
command and the -M
flag to perform the migration.