Oracle DB and SAN

[Sylvain CROUET]

Hi!

I would like to know if someone has already saved an Oracle DB with a SAN architecture, without any other product like RAC or VERITAS.
The idea is: I have two servers with an Oracle DB. Server A is the main server and server B is on a backup site, in standby mode. I would like to save my Oracle DB on server A to server B, without stopping the database, and frequently enough in order not to lose more than one hour of data. Is this possible?

[Michael Steele_2]

You can you export and set up hourly ftp crons?

[Sylvain CROUET]

I do not think FTP would be the solution regarding the database consistency.
I think that a bit to bit copy through the SAN would be more efficient.

[Steven E. Protter · Accepted solution]

Shalom,

Suggestions:
1) Oracle dataguard. Does block replication from one system to another. Much less i/o and band width requirements than Serviceguard clustering.
2) Serviceguard clustering. High availability, you can take backups to other disk storage(hot) any time you want by putting the database into backup mode.
3) Oracle streams. Takes the sql being run on production database and runs it on a secondary copy database. Usually the sql is much less in size than say copying the data blocks.

SEP

[Sylvain CROUET]

Does Oracle Dataguard and Oracle streams work with an Oracle 9.x DB? Is there any distance limit with this solutions (eg: backup should not be located more than 50 kilometers from primary)?

Is it possible to have a correct backup with Oracle and SAN only, without any additional software?

[Indira Aramandla]

Hi Sylvain,

Oracle Streams was introduced since Oracle 9i release 2 (9.2). This enables the sharing of data and events in a data stream, either within a database or from one database to another

Here is in brief "when to use Streams and when to use Data Guard".

Streams are used for Information Sharing/Distribution, Multi-Directional, Data sub-setting. It allows heterogeneous platforms. Tablespace can be READ WRITE. Allows data to be shared between oracle and non-oracle datastores.
Data Guard is used for Disaster Recovery and High Availability, It is uni-directional. Provides maximum Data Protection. Automated switchover and failover. But only Homogenous platform are permitted. Tablespace should be READ ONLY. Redo Apply and SQL Apply can be done with Oracle databases only
In summary, if you require a logical standby database for data protection, use Oracle Data Guard. Oracle Data Guard is designed specifically for the creation and management of a logical standby database. It automates many of the common tasks, reducing the need for custom management scripts. On the other hand, Streams provides much finer granularity and control over what is replicated and how it is replicated. Streams supports bi-directional replication, transformations and custom apply functions. It also gives users complete control over the routing of change records from the primary database to a standby database. This allows users to build hub and spoke network configurations that can support hundreds of replica databases.

Refer to Note:300223.1 in Oracle metalink for "Comparative Study between Oracle Streams and Oracle Data Guard"


Indira A

[Frank de Vries]

Hi,

We use business to bussiness copy (that is what it is called ) but it is effectively
a bit to bit copy of partititions attached
to the lun's.

The software comes from HP and runs on XP256 or XP512 (Basically an HITACHI technology)

The only snag is that we do not use a standby mode. We do not trust the write behind buffers, and stop the db for a tick and bring it up completely mirrored.

[Sylvain CROUET]

Hi Franck!

Can you be more precise? What is the name of the software solution? How is your DB configured?

[Joshua Small_2]

The do it yourself solution involves a regular backup (no reason you can't do this online) and having Oracle write Archive logs to a remote server.

These can be written locally and rsync'ed to another box, and despite not involving a big name product, is quite a reliable procedure.

[Frank de Vries]

Hi Sylvain

We use the HORCM raid manager for Hpux
platforms , they work with the XP256 and XP512 systems.

Please find attached the conf file with
loads of technical details. That will give
you more inside into how the Raid manager
uses LVM linked to LUN to setup
business-to-business copy at disk level.

If you need more info let me know.