||Donald K. Burleson
Oracle RAC Tips
Configure using HACMP/ES
As discussed earlier, the HACMP method may involve the use of
concurrent logical volume groups. The HACMP layer includes the concurrent
logical volume manager (CLVM).
HACMP/ES installation has many steps, which include:
Installing and setting up the
Installing the AIX operating
Installing the latest
maintenance and required patches.
Installing the HACMP/ES on
each node and applying patches.
Configure the Cluster Topology
This step involves using smit hacmp menus to configure the cluster
details. All configurations are done from one node and then synchronized
to the other participating nodes. Adding a cluster definition process
requires the information such as cluster id, cluster name, nodes, and
adapter details to be supplied. After the topology is configured, it has
to be synchronized with other nodes. Main steps for implementing an HACMP
Configure the cluster: Select
‘Add a cluster definition’ - In this step the cluster must be given an
identifier and a name.
Configure nodes of the
cluster: Select ‘Add cluster nodes’. Here, the names of the nodes
participating in the cluster are entered.
Configure the network: Select
‘Add an adapter’. Provide details such as Adapter IP label, network
type, and network name, etc., for each node.
In the case of the implementation of a concurrent volume group, only a
private network is needed. It’s not necessary to define boot, service, and
standby addresses as it is in cascading or rotating HACMP configurations.
In RAC environments, a high performance private network between machines
participating with the RAC cluster will be needed. The network type of
this interconnect can be HPS (High Performance Switch) or Ethernet (use a
gigabit Ethernet, for example). Note: It is also advisable to have a
non-IP network (like RS/232 or Target mode SSA).
Next step is to synchronize the cluster topology. The synchronization
performs topology sanity checks, as well as pushing the configuration data
to each of the nodes in the cluster configuration.
To synchronize, use the fast path command smit configchk.dialog.
Configure a Resource Group
In a RAC configuration, creation of a resource group is required. This
resource group is a concurrent group for a shared volume group. The
following steps add a resource group.
- First, the Volume Group that is shared between the nodes must be
created. The Oracle instances residing on multiple nodes share the
volume group concurrently. The concurrent logical volume manager manages
the volume group. The HACMP layer includes the CLVM, which enables the
concurrent logical volume manager.
CLVM only works under the HACMP environment. Oracle will not allow
VSD(s) and concurrent logical volumes (CLV) to be used on the same
database. If PSSP services are being used, Oracle will report an error
if the customer attempts to use CLV. If HACMP services are used, Oracle
will report an error if the customer attempts to use VSD(s). When using
CLVM or HACMP, the environment variable pgsd_subsys should be set to
Using the smit vg and then
selecting the add a volume group option creates the volume group.
Provide the group name, disk details, major number, etc. The volume
group should not be activated automatically.
Create the necessary volumes
for use by the Oracle installation and database creation by using the
Change permissions on the
character devices so the software owner owns the volumes with the chown
Then, import the volume group
to the other nodes. First, varyoff on the first node, then import the
definition of the volume group using smit vg – select the ‘import a
volume group’ option.
After importing the volume to
each of the nodes in the cluster, change the ownership of the character
devices to the software owner ‘oracle’.
Now, create a concurrent
cluster resource group that manages the volume group created in the
Use the smit cm_add_grp with
option add a resource group. Configure the node relation as concurrent,
which indicates that the multiple nodes share the resource group.
Specify the list of nodes that share this resource.
The next step is to
synchronize resources by using the smit hacmp menu.
Now start the cluster
services using the smit hacmp menu.
So far, we have assumed that the volume group has the only volumes and
that they will be presented to Oracle as the raw devices. However, with
the availability of the General Parallel File System (GPFS), we have the
option of setting up the cluster file system for the use of Oracle
database files. The next section explains the features of the GPFS.
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