Re: Node Affinity Awareness = faster disk access in a custer. WHAT?

Scott,

I had the similar question sometime back and found that was an old feature on 8i versions (when the storage is attached to one node ) . This is not applicable to current versions.

Having said that, it is not really a complex feature to implement as we record the services times for the files (or asm disks) locally and a simple call to KCFIO data structure will reveal the truth.

-Gopal

On Apr 30, 5:04 pm, "Scott" <nos..._at_nomail.com> wrote:
> I was reading the docs and came across the following
>
> http://download-east.oracle.com/docs/cd/B19306_01/rac.102/b14197/back...
>
> In some cluster database configurations, some nodes of the cluster have
> faster access to certain datafiles than to other datafiles. RMAN
> automatically detects this, which is known as node affinity awareness. When
> deciding which channel to use to back up a particular datafile, RMAN gives
> preference to the nodes with faster access to the datafiles that you want to
> back up. For example, if you have a three-node cluster, and if node 1 has
> faster read/write access to datafiles 7, 8, and 9 than the other nodes, then
> node 1 has greater node affinity to those files than nodes 2 and 3.
>
> I am having a hard time accecpting this statement mainly because I don't
> want to believe it is true, but then why is it printed. (Maybe they get
> around it by saying "some cluster databases") Does anyone have any
> experience with this issue and where it may show up?
>
> Thanks
> Scott.

--
Best Regards,
K Gopalakrishnan
Co-Author: Oracle Wait Interface, Oracle Press 2004
http://www.amazon.com/exec/obidos/tg/detail/-/007222729X/

Author: Oracle Database 10g RAC Handbook, Oracle Press 2006
http://www.amazon.com/gp/product/007146509X/