Re: RAC in NAS

On 07/26/2006 09:10:03 PM, Mark Brinsmead wrote:
>
> A more relevant question to ask is whether the customer actually *needs*
> RAC. Or 8 CPUs. If they had not done enough research to know whether the
> storage layer they had chosen would even work, then chances are, they have
> not sized the hardware nor adequately researched the requirements for RAC,
> either.

Horizontal scaling is also known as crucifixion. RAC implementation without careful planning and analysis is just that.

>
> If you're *certain* that you *must* use NAS (NFS), then be certain you do
> your homework when choosing your other components. (Oops. That's how we
> got here, isn't it?) Redhat cannot (yet) support Asynch I/O with NFS -- the
> same may be true of other supported Linux distros, but I'm not certain.
> Perhaps you could use Solaris? [Ooh! Wouldn't *that* annoy IBM... ;-) ]

Asynch I/O is not that important. Oracle can emulate it using I/O slaves. Granted, it's not as good as the real thing, but you will not sufer much, either. Direct I/O is much more important and it is supported. FC5 is the sign of things to come. It does support full NFS4 version, with cient caching and async I/O included. EL5 is likely to have those features, minus bugs, discovered by free beta testers, like me.

-- 
Mladen Gogala
http://www.mgogala.com

--
http://www.freelists.org/webpage/oracle-l