Re: San-Based replication VS DataGuard replication

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Date: Thu, 9 Oct 2008 12:50:50 -0700 (PDT)
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Hello *,

I believe both technologies have its strengths and weakneses.

I have been using Data Guard as the primary DR solution. It works great in situations where everything (or most of it) that you worry about is the database. The switchover is reasonably fast and depending on configuration can provide you with minimal or no datalos anfter the failover. The problem starts if you have to worry about other nondatabase  stuff that is needed on the recovery site also. The ftp, samba, application server, etc. make good examples. Althou these are usually seldom changed there has to be a mechanism put in place that will synchronise its data too. Althou it seams simple at first it is a real pain in the ass.

We use the Data Guard configuration with Oracle E-business Suite - as recomended solution by Oracle to provide the DR capabilities. The database configuration is easy but the synchronisation, refreshes and preconfiguration of application server is a nightmare. We were running the DR tests and althou the database is switched over in 10 minutes the whole switch to the backup site takes about 3 hours thanks to varius application refreshes, reconfigurations, etc.

This all makes the whole switchover experience a very time consuming, but most important complicated experience. The documentation of the process has about 60 pages and needs experienced DBA to make it happen.

With the storage or filesystem replication all this is gone - as neither the database or application are aware of it. Simplicity is preserved - which is a huge bonus. The only thing I see dangerous is that doing "rm -Rf" will replicate to the standby site just fine damaging both sites. With standby you can still failover.

To sum things up - with simple things - database + end clients = go with the standby database. With anything more complicated I would chose storage or filesystem replication.

Remigiusz Boguszewicz Received on Thu Oct 09 2008 - 14:50:50 CDT

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