Cross-Platform Migration using Heterogeneous Data Guard
- by Roy F. Swonger
Most people think of Data Guard as a disaster recovery solution, and it certainly excels in that role. However, did you know that you can also use Data Guard for platform migration under some conditions?
While you would normally have your primary and standby Data Guard systems running on the same OS and hardware platform, there are some heterogeneous combinations of primary and stanby system that are supported by Data Guard Physical Standby.
One example of heterogenous Data Guard support is the ability to go between Linux and Windows on many processor architectures. Another is the support for environments that are running HP-UX on both PA-RIsC and Itanium hardware. Brand new in 11.2.0.2 is the ability to have both SPARC Solaris and IBM AIX on Power Systems in the same Data Guard environment. See My Oracle Support note 413484.1 for all the details about supported platform combinations.
So, why mention this in an upgrade blog? Simple: much of the time required for a platform migration is usually spent copying files from one system to another. If you are moving between systems that are supported by heterogenous Data Guard, then you can reduce that migration downtime to a matter of minutes. This can be a big win when downtime is at a premium (and isn't downtime always at a premium? In addition, you get the benefit of being able to keep the old and new environments synchronized until you are sure the migration is successful!
A great case study of using Data Guard for a technology refresh is located on this OTN page. The case study showing CERN's methodology isn't highlighted as a link on the overview page, but it is clickable.
As always, make sure you are fully versed on the details and restrictions by reading the available documentation and MOS notes. Happy migrating!
