Re: ASM Question - Best Practice
Date: Wed, 04 Jun 2008 19:49:56 +0100
K Gopalakrishnan wrote:
> Good that you are asking the questions at planning phase (!),
> The choice is totally yours. If you think your SAN mirroring is better
> than ASM you can use SAN mirroring and choose the external redundancy
> to ASM. In short, ASM mirroring is done at the 'server' level and SAN
> mirroring is done at 'controller' level. So there may be some
> additional CPU overheads in ASM mirroring which may or may not be an
> However with ASM mirroring, you have the luxury of having many disk
> groups with different redundancy levels, like double or triple
> mirroring for system/data and no mirroring for temp tablespaces and so
> on. You can do the same at SAN level, but that is not as simple as you
> do in ASM.
> Also you don't need to reserve a hot spare for ASM mirroring as ASM
> mirrors the 'extents' which are just 1M pieces of storage blocks (aka
> allocation units). This gives a better utilization of available disks,
> but doesn't matter these days!!
Thanks Gopal, and to all others who responded. It'll be interesting to see what Frank has to say about the "bug pit". I hope he will amplify.
Palooka Received on Wed Jun 04 2008 - 13:49:56 CDT