3 node cluster

[nasmel]

Hi

anybody please guide me how to create a 3 node serviceGuard Cluster .i need to setup a 3 node cluster for Oracle RAC with ASM disk.

[johnsonpk]

Hi Nasmel,

Check the below link, i guess this doc is fair enough to start with

docs.hp.com/en/8365/SGeRAC_10g_Sample_Config.pdf

and here is the one which we used as a reference in our installation
http://www.scribd.com/doc/12775334/Oracle-RAC-11g-R1-On-HPUX

Johnson

[nasmel]

hi

can you please tell me what are the things i need to consider while configuring 3 node cluster.is it same as 2 node cluster?

[Turgay Cavdar · Accepted solution]

There is no special thing, repeat every step you did for while preparing the other nodes, dont forget to populate the files with new node : /etc/cmcluster/cmclnodelist, /etc/hosts...

[johnsonpk]

No difference ..You have got one more server to configure ..
it would have been different if you decide to go for more than 4 nodes as cluster lock disk support limit up to 4 node

Johnson

[nasmel]

Thanks ..

[nasmel]

Do i need to create a lock disk in 3 node cluster ?
if i create a lock disk will it create a split brain situation?

[Turgay Cavdar]

"Lock Requirements
A one-node cluster does not require a cluster lock. A two-node cluster requires a cluster lock. In clusters larger than three nodes, a cluster lock is strongly recommended. If you have a cluster with more than four nodes, use a quorum server; a cluster lock disk is not allowed for clusters of that size."

So in the document for 3-node cluster cluster lock stated as "strongly recommended". If you dont use cluster lock disk on 3-node cluster, there can be some bad senarios for you. Lets say one node is down for maintenance, and there is a split brain happened in the remaining two nodes, as there is no cluster lock, your cluster entirely become unavailable. So use a cluster lock...

[johnsonpk]

>>Do i need to create a lock disk in 3 node cluster ?
**Cluster lock (The cluster lock is implemented either by means of a lock LUN or a quorum server) is required for two node cluster
**"cluster lock DISK "recommended and supported up to 4 node cluster
>>if i create a lock disk will it create a split brain situation?
Cluster lock is used as a tie-beaker to avoid split brain situation


more details can be found on
http://www.docs.hp.com/en/B9903-90054/ch03s02.html