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service This is the one of the first pieces of info you need for the /etc/cluster.conf file.
$ mkqdisk  l HA585  c /dev/mapper/qdisk
By convention, the label is the same name as the cluster; in this case, HA_585. The section of the
cluster.conf file looks like the following.
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Chapter 3. Software Installation and Configuration
log_level="5"/>
Tip
You may need to change the maximum journal size for a partition. The following procedure
provides an example of changing the maximum journal size of an existing partition to 400MB.
tune2fs -l /dev/mapper/vg1-oracle |grep -i "journal inode"
debugfs -R "stat " /dev/mapper/vg1-oracle 2>&1 | awk '/Size: /{print $6}
tune2fs -O ^has_journal /dev/mapper/vg1-oracle
tune2fs -J size=400 /dev/mapper/vg1-oracle
Warning
Fencing in two-node clusters is more prone to fence and quorum race conditions than fencing in
clusters with three or more nodes. If node 1 can no longer communicate with node 2, then which
node is actually the odd man out? Most of these races are resolved by the quorum disk, which is
why it is important for the HA case, and mandatory for RAC/GFS.
RAC/GFS Requirement
Red Hat Cluster Suite must be implemented with qdisk, or the configuration is unsupported. Red
Hat Cluster Suite has to retain quorum to support a single, surviving RAC node. This single-node
operation is required for certified combinations of RAC/GFS.
3.3. Network Topology
A cluster s network is either complicated, or really complicated. The basic cluster involves several sets
of logical network pathways. Some of these share physical interfaces, and some require dedicated
physical interfaces and VLANs, depending on the degree of robustness required. This example is based
on a topology that Red Hat uses to certify Oracle RAC/GFS, but is also suitable for the HA configuration.
Tip
Cluster networks require several VLANs and multiple address assignments across those VLANs.
If bonds are going to span VLANs or switches, then it might be required to use ARP to ensure the
correct behavior in the event of a link failure.
3.3.1. Public Network
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Red Hat Enterprise Linux 5 Configuration Example - Oracle HA on Cluster Suite
The public network is the pathway used by the application tier to access the database. The failure
scenario is the loss of an entire node, so although bonding does provide protection in the event of the
public interface failure, this is not as likely. Bonded public interfaces complicate application tier network
configuration and failover sequencing. This network is not bonded in our example.
The hostnames of the server nodes are identified by the public address. All other network interfaces are
private, but they still may need addresses assigned by network operations.
RAC/GFS Considerations
Oracle Clusterware (CRS) creates it s own set of Virtual IPs (VIP) on the public interface. This
mechanism makes it possible for CRS on another node to provide continued access to the failed
node s specific public address. Bonded public interfaces, in the presence of CRS VIPs, are not
recommended. See Oracle SQL*Net Configuration in both the HA and RAC/GFS Chapters.
3.3.2. Red Hat Cluster Suite Network
The Red Hat Cluster Suite network is used by CMAN to monitor and manage the health of the cluster.
This network is critical to the proper functioning of the cluster and is the pathway that is bonded most
often.
RAC/GFS Considerations
RAC requires GFS clustered file systems, which utilize the Distributed Lock Manager (DLM) to
provide access to GFS. The Oracle Global Cache Services (GCS) is often configured to use this
pathway as well. There is a risk of overloading this network, but that is very workload dependent.
An advanced administrator may also choose to use Infiniband and Reliable Data Sockets (RDS)
to implement GCS.
The network is private, and only ever used by cluster members. The dual-ported e1000 NIC is used for
the Red Hat Cluster Suite hearbeat service or Oracle RAC Clusterware services.
The file /etc/modprobe.conf contains all four interfaces, and the two ports of the e1000 will be [ Pobierz całość w formacie PDF ]