topic Re: 4 Node Cluster/2 Node RAC/Failover RAC in Operating System - HP-UX

4 Node Cluster/2 Node RAC/Failover RAC

Austin Hackett — Fri, 26 Sep 2008 13:31:09 GMT

Hello Forum

I am used to working in MCSG environments where there is a cluster node and a disk array in each data centre and the active node writes to both disk arrays via LVM mirroring. However, I am wondering whether the following setup is a supported configuration:

A 4 node SG cluster with 2 nodes and a disk array in each data centre - the two active nodes can write to both arrays via SLVM mirroring. The active nodes (in data centre A on disk array A) host an 2-node Oracle RAC package and in the event of disaster the RAC package can failover to the failover nodes (in data centre B on disk array B). The environment would be using SGeRAC and SLVM.

In essence, I suppose I am asking whether SLVM can allow multiple nodes to write to mutiple arrays.

I am aware that the typical approach here would be a Data Guard physical standby and a 2-node RAC in both data centres with SGeRAC used locally on each RAC and Data Guard dealing with disaster recovery, but am curious as to whether the scenario proposed above is possible.

Any help would be greatly appreciated

Thanks

Re: 4 Node Cluster/2 Node RAC/Failover RAC

Steven E. Protter — Fri, 26 Sep 2008 13:59:43 GMT

Shalom,

LVM mirroring will work as you say. HP-UX 11.31 has multipath built into the OS.

For performance reasons I recommend avoiding software mirror and doing this configuration on the hardware.

SEP

Re: 4 Node Cluster/2 Node RAC/Failover RAC

Austin Hackett — Fri, 26 Sep 2008 14:09:33 GMT

Steven

Many thanks for your response. Do you know happen to know whether the scripts supplied with SGeRAC will take care of starting Oracle Clusterware on the failover node and so on or whether you need to "roll your own"?