RE: Multiple Instances and 9iRAC

[Thompson, Todd]

Sorry I didn't explain the configuration very well-  here is what I'm talking about:   We have an existing HP server currently running 4 instances/databases.  Sid1,sid2,sid3,sid4   Is it advisable to implement RAC for all the databases/sids on this server?   i.e.   Cluster1= Node1= Sid1,sid2,sid3,sid4 Node2= Sid1,sid2,sid3,sid4 Node3= Sid1,sid2,sid3,sid4 Node4= Sid1,sid2,sid3,sid4   Or does each cluster  need to manage a single instance.......   Cluster1= Node1= sid1 Node2= sid1 Node3 =sid1   Cluster2= Node4=sid2 Node5=sid2 Node6=sid2   Cluster3= ....   What we are envisioning is a single huge RAC cluster that will run ALL of our Oracle databases vs. created multiple RAC clusters with one instance/database per cluster.     -----Original Message----- From: Arup Nanda [mailto:[EMAIL PROTECTED] Sent: Friday, March 14, 2003 2:20 PM To: Multiple recipients of list ORACLE-L Subject: Re: Multiple Instances and 9iRAC   Todd,   RAC is a multi-instance database. If you have n nodes in a cluster then you generally have (although not necessarily that many) n instances accessing the same database. When you mention 3 or more Oracle instances, perhaps you mean 3 or more "databases" each in a separate cluster of 4 to 8 nodes each.   Interconnect plays a very important role in performance in this case and depends heavily on the hardware you decide on. For instance if you use Tru64 Clusters on Compaq alphas, you would probably go for Memory channels as interconnect; but for HP clusters you will lean towards CLIC interface.   The environment you mentioned is not just viable, but that's exactly how it is done.   HTH.   Arup Nanda ----- Original Message ----- From: Thompson, Todd To: Multiple recipients of list ORACLE-L Sent: Friday, March 14, 2003 1:29 PM Subject: Multiple Instances and 9iRAC     My company is currently considering using Oracle 9i RAC. One of the proposed environments is to have multiple oracle instances (3 or more) configured on a 4-8 node RAC cluster. Does anyone have any insights as to the viability of this implementation?  Will the high speed inter connect be able to handle the traffic from multiple instances?  I always thought of RAC as a single instance implementation with each instance needing its own cluster...........