Solaris

Hello everyone
I've inherited an Oracle Solaris system holding ASE Sybase databases. The system consists of two nodes inside a Sun Cluster. Each of the nodes is hosting 2 Sybase database instances, where one of the nodes is active and other is standing by. The scenario at hand is that when any of the databases on one node fails for whatever reason, the whole system gets shifted to the second node to keep the environment going. That works fine.
My intended scenario:
Each node is holding 2 database instances, both nodes ARE working at the same time so that each one is serving one instance of the database. In the event of failure on one node, the other one should assume the role of BOTH database instances till the first one gets fixed.
The question is: is that possible? and if it is, does that require breaking the whole cluster and rebuilding it? or can this be done online without bringing down the system?
Thanks a lot in advance

Your intended scenario requires that the database files are stored on a shared disk system (SAN). The description you gave sounds, as if in the current setup, each instance has its own local disks.

You need one cluster resource group (rg) per instanz, where each rg is formed by at least three resources: the shared disk resource, the database instance resource and a logical hostname resource, controlling an IP address, which fails over from one node to the other.

If my assumptions are right, it can't be done without an extensive maintenance window.

Thanks hergp
Yes we do have a shared storage among both nodes containing the data files. Did this "maintenance window" implies that we break and rebuild the whole cluster?

You don't have to rebuild the cluster, you just have to create the resource group and the cluster resources within. If the database is already on a shared storage, it might be only a short service interruption.

You also have to check the requirements for the cluster agent for sybase. I did a similar setup with DB2 and there were some additional requirement to be met, like having the instance owner home directory on the shared storage as well (in this particular case on a globally mounted cluster filesystems).