RE: Oracle Rac and IBM P-series machines

  • From: "Pete Sharman" <peter.sharman@xxxxxxxxxx>
  • To: "Thomas.Mercadante@xxxxxxxxxxxxxxxxx" <Thomas.Mercadante@xxxxxxxxxxxxxxxxx>, "oracle-l@xxxxxxxxxxxxx" <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 16 Feb 2006 05:46:53 +1100

Generator Microsoft Word 11 (filtered) Tom

No, it is not true that you need to use raw devices because of RAC. You need to 
use raw devices ONLY where the OS can' t share files between nodes. If you were 
on a real operating system (also known as VAX) this wouldn' t be a problem.

OK, OK, I' m biased! J 

Honestly though, this is an OS limitation that RAC has to work with, rather 
than necessarily a RAC limitation. If the OS you use supports a CFS, you can 
use that instead. Alternatively, you could use ASM if you' re looking at 10g.

We do have customers with systems that are further apart than a mile, mostly I 
think using dark fibre (or dark fiber for you Yanks). Again, the limitation 
here is more of an OS one. If you can cluster the boxes, RAC should work on top 
of that. Having said that, there is of course a latency issue that gets worse 
as you move the boxes further apart. Only testing of your specific app in that 
environment can tell whether that latency is acceptable or not.

HTH.


Pete

"Controlling developers is like herding cats."
Kevin Loney, Oracle DBA Handbook

"Oh no, it's not. It's much harder than that!"
Bruce Pihlamae, long-term Oracle DBA
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Mercadante, Thomas F (LABOR) Sent: Wednesday, 15 February 2006 6:10 
AM To: oracle-l@xxxxxxxxxxxxx Subject: Oracle Rac and IBM P-series machines

All,
We have a pair IBM P690 machines running AIX 5.3.

I was wondering if anyone is running RAC on these machines. 

Is it true I would need to use RAW devices because of RAC? " Normal"  file 
systems would not work for RAC.

And can the machines be geographically apart from each other (like within a 
mile)?
Last I heard the physical distance was a problem, but things change fast around 
here.

Thanks
Tom Mercadante

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