Oracle high availability

[Roberto1979es]

Hello, I have one Oracle Database in one Visa server (2 processors 2.8 Ghz, 4 GB Ram, 6 hb 250 gb in RAID 5) with Windows 2003 Server. Also, I have another Visa Server (3.0 GHz intel xeon, 4 GB Ram, 6 hb 250 gb in RAID 5 + hotspare). I want to make a system with High Availability, because in my work we have a real time application. Actually, every nigth I have a backup of my database with the export utility. If one day the first server failover. I have a complete copy of yesterday, but I loss data of today. I want one system for high availability and it does not loss of data.

First, I want to make a cluster service with Oracle RAC, but I need a SAN or anything similar. My servers have 6 hard disk or 250 GB for each one. Both are in RAID 5. I'm finding in internet but I don't find anything that How can I make Oracle RAC with my hardware.

After, I think of build Oracle Data Guard. My first server have a primary database and my second server have my standby database. I want to use GUI grafical, but I look at the option in enterprise manager web, but I don't find it. I find the DGMGRL but I know very well how create the standby database. I have reading the oracle documentation but I don't know how it is.

Somebody can help me,please??
PD: I use Oracle 10 Release 1.
Excuse me but I'm spanish and my English is very very very bad.

[skhanal]

First you have to change your backup strategy. Export is not good enough for your application. You should use RMAN or hot backup and backup archive log files.

Oracle RAC provides high availability and performance scalability. For this you need a shared storage (not necessarily a SAN). The disks should be accessible from both the servers.

Data Guard is a high availability solution too. It is geared toward disaster recovery solution.

[Roberto1979es]

What solution do you recommend me?
I want that if a server fails, then the another server works and the users don´t know that one server is failed. Can you explain me how can I make a Oracle RAC without a SAN ? Do you refers that the storage can be internals in the computers (SATA) and connected with the another server with the network interface ?

thanks you very much

[skhanal]

RAC works with external storage, so I don't think you can connect two servers internal disks to make it work.

If you don't have external storage then your choices are limited. Even Failsafe needs external storage.

You can implement Data Guard in this situation but it may not be transparent to user. When primary fails the secondary can be brought up using Data Guard broker but you have to make sure your TNSNAMES.ORA is properly configured to fail over to secondary. Check Transparent Application Failover concept in Oracle documentation.

[Roberto1979es]

Do you know any applications GUI for Oracle Data Guard ? I tried with the enterprise manager web, but I don't look the option.

Well, if it's not transparent to user that doesn´t very very important. The most important for me it's have a high availability and the time of recovery system it's very short.
Have you any ideas for a GUI dataguard application?

[skhanal]

You have to setup Enterprise Grid Control application, which is a different beast, which needs its own database and application server.

[Roberto1979es]

ok, thanks very much. My problem was that I did not install the Enterprise Grid Control. Now, I have install the Enterprise Grid Control, and I see the link of the DataGuard Configurations. However, when I installed, the last friday, the Enterprise Grid Control, everything work fine, until this morning. Today I tried to connect to my database but I didn't it. Oracle show an error, Ora-12557 (Tns Protocol). Then, I tried in another pc. I install:
1.- Oracle Database 10g
2.- Oracle Grid Control with new Database (empre) for the control.
3.- I tried to create a new database, but in the creation Oracle show an error Ora-12557 and Ora-12560.

Have you any idea?

[skhanal]

Is the Oracle agent running in your database?. Are the management server and database server in the same subnet or there is a firewall between them?

Depending on your network configuration, the management server and database communicate on different port.

[Roberto1979es]

This morning, I have formated my server, and I have installed the windows 2003 server standard edition again (new installation). After, I have installed the Oracle database 10g with a new database (I called it, emRep). After I create a new database (it's will be my production database). After I install the Oracle Grid Control. Today, when I'm installing the Oracle Grid Control I want to be select the second option (Existing database for repository), but Oracle says me that the database will be a 9.2.4.0 version or 10.0.3.0 version. (I have 10.0.2.0) Therefore, I select the third option (Only Agent). [Yesterday, I probe with the first option, create a new database for repository]. When the installation was completed the Oracle errors Ora-12557 appears again. All Oracle products, Oracle database and Oracle Grid Control, was installed in one server for testing purpose. I don`t have any firewall, and I don`t know which port use, and I don´t know how change or managed. I want to connect with my database but I can't. I tried with SqlPlus and I tried with http:\\<server_name>:80\em. However, I connect with http:\\<server_name>:5500\em with emRep database, but not with the another database.

[skhanal]

When you install grid you have to create a database with that, you can upgrade to later version afterwards.

With the first option, make sure you have tnsnames.ora and sqlnet.ora file in network\admin folder of OMS home. There should be an entry for emrep in your tnsnames.ora

[Roberto1979es]

Ok, then I have to copy tnsnames.ora and sqlnet.ora file in network\admin folder ? Can you send me any sample of these files? or tell me how can I create the entry for emrep in tnsnames.ora?

[skhanal]

There should be a sample under network\admin\sample folder. Or you can use Net Configuration Manager tool to create one.

[Roberto1979es]

ok, I copy my tnsnames.ora and sqlnet.ora file in network\admin, but I didn´t connect with the database. If I launch Net Configuration Assistance does not appear, however if I launch net configuration yes appear, but I didn´t connect with the database.

[skhanal]

You can either edit tnsnames.ora and sqlnet.ora file to put connection information such as service_name and host for your database, if you are not familiar with that Net Configuration Manager is the way to create one using GUI.

Please read Oracle Networking documentation at http://tahiti.oracle.com