Sample Configurations with SGeRAC and Oracle RAC 10gR2, March 2009

Figure 6. Dual primary and standby Ethernet including GAB/LLT

Figure 6 shows the same variation as figure 3 except this configuration is for CFS and CVM. This

configuration is for heavily loaded configurations where RAC-DB-IC traffic interferes with heartbeats

and other cluster communications. Placing RAC-DB-IC traffic on a separate network allows more

aggressive SG-HB timeout values. The drawback is that the RAC-DB-IC should be monitored so

network failures can be detected sooner than the Instance Membership Recovery (IMR) timeout and

recovery can be started earlier.

Storage high availability

Storage HA is available at several levels, as follows:

• Redundant links to the same disk device.

• Storage arrays provide redundancy at the disk level.

• Volume Manager mirroring to multiple devices, for example by SLVM or CVM.

• Multiple copies on multiple disks.

OC relies on the platform to provide transparent redundant links to the same device. OC provides

redundancy for the Oracle Cluster Registry (OCR) by providing mirroring capability, and thus disks

from JBODs (“just a bunch of disk”) can be used. When JBODs are used and the disk themselves are

not highly available, two physical disks are required to protect against link failure and disk failure. In

the case of redundancy for the Voting disk, three of more copies, that is disks, are required.

When redundant links and storage arrays are used, the configuration of OC is simplified by

configuring a single OCR and Voting disk with HA provided by SLVM, CVM, and/or storage array.

Multiple nodes

Multiple nodes protect against failures at the system node level. For cluster HA, a minimum of two

nodes is required.

Power

Redundant components should be separately powered so that a single power failure does not impact

all nodes, all switches, and/or all storage.

Node A

LAN 1

Node B

GAB/LLT

Private

(primary)

Private

(standby)

Private

(primary)

LAN 1

LAN 2

CSS-HB

GAB/LLT

Private

(standby)

LAN 2

LAN 4

LAN 3

RAC