Oracle with MCSG

[Karthik S S]

Hi,
I understand that HA for Oralcle can be configured in 3 levels.
1. Single Instance Oracle with MC/ServiceGuard
2. Oracle Parallel Server with ServiceGuard OPS Edition
3. Oracle Parallel Fail Safe with ServiceGuard OPS Edition

I have tried OPS with SG (2 node) where the installer distributes the Oracle binary files to the local filesystem of both the nodes and database files will be kept in a shared storage. But If I go for the Single instance Oracle do I need to install oracle on both the nodes? Or installing the application binaries and datafiles on shared storage will do?? Kindly let me know.

Thanks
Karthik

[Justo Exposito]

Hi Karthik,

I have Oracle in a two nodes MC/ServiceGuard and we have installed the Oracle binaries in both nodes in the internal disks, this is better than in the shared storage, because if you want to have different configurations in your instances you can, if you must to apply patches to your Oracle product you can to do in one node and if all works fine apply in the other, etc...

As I ear, install parallel server in Oracle is complex, and the Spanish Oracle people tell us if you want to configure a parallel server you need us.

Hope this helps,

Justo.

[melvyn burnard]

If you install Oracle binaries on your shared storage, you are running a grave risk of thing sbeing unavailable when you need them.
Also, if you need/want to upgrade, you will have to halt the package, during hte upgrade etc. Just a few things to think of.
It is far better to have the binaries installed on each and every node in the cluster.

[Christian Gebhardt]

Hi
in our environment typically oracle is installed in a MCSG-Package, every database has it's own installation. If you switch the package all binaries, datafiles, ... switch to the other node.
We separate binaries (/u01/app), redo's (/u01/redo), arch's (/u01/arch), datafiles (/u01/oradata) on different volume groups.

We are running up to 20 databases in several Cluster-Environments, each database has it's own Installation in a own MCSG-package. So we can have different Oracle-Releases, Patch-levels, ...

Hope this will help
Chris

[Karthik S S]

Hi,

If I have to install the binaries on both the nodes how should I go about that? DO I have to start the installer when the cluster is UP?. And also if I create a database on one machine how can the other node can access the database (Considering that the original node is down). What are the files I need to copy from the original node to the secondary to make it possible to mount the database??

Thanks
Karthik

[Karthik S S]

Hi Gebhardt,

When you say that you have configured oracle as a package and kept the binaries and datafiles on the shared storage I am assuming that you would have done the installation from a single node. So other than the shared storage data, does the oracle installer not write data/configuration info on any other local filesystem location? (like the oratab file in /etc). If so what are the files that are need to be copied manually to the other node??. Pl. let me know

Thanks
Karthik

[Christian Gebhardt]

Hi Melvyn

If you install oracle on every node (think of a 3 Node Cluster) you have to maintain 3 oracle Installations, need storage for 3 oracle installation (local on every node)

If you update to new release you have to upgrade 3 installations, so you temporary need space for 6 installtion ?

Chris

[Christian Gebhardt · Accepted solution]

Hi

you have to keep equal two files on every node:

/etc/oratab
/var/opt/oracle/oraInst.loc

- First file you need if you use tools like "Intelligent Agent"
- Second file is the configuration file from "Oracle Universal Installer"

Chris

[John Palmer]

This is another 'it depends' question...

If you only intend running Oracle on one node then it makes sense to install Oracle on your shared storage and make it part of the Serviceguard Package.

Many people want to use the standby node as a test server rather than leave it sitting idle so would install Oracle on there as well. In this situation, you can still choose to have the Oracle software as part of your package by using different Oracle Home directories or you can use the server specific installation.

I've got systems that use both methods.

If you want to go for server specific installations, you can get away with only installing Oracle once and copying it to the other servers...

1. Ensure your servers are patched to the same level.
2. Ensure you have Oracle's user and group set-up on all servers.
3. Install Oracle on one server.
4. Backup your Oracle filesystem and restore it to the same mountpoint on the other server(s).
5. Copy /etc/oratab and /var/opt/oracle/oraInst.loc to the other servers.

Regards,
John

[Karthik S S]

Hi Chris/John,

Considering the Diskspace restraints and a possible upgradation of Oracle I have decided to install Oracle binaries also on the Shared storage. Thanks for your valuable inputs.

Thanks
Karthik