From: Martino Piccinato
Date: July 12 2005 7:34am
Subject: Re: can mysql use the shared-storage .
List-Archive: http://lists.mysql.com/cluster/2163
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Stewart Smith wrote:

> MySQL
>Cluster lets you work out your disk bandwidth requirements per-node for
>the checkpoints. It is extremely unlikely that you're going to need high
>bandwidth for this, so you save a heap on storage.
>
>  
>

could you please explain better this latter thing? I can't exactly 
understand what you mean.

As for shared nothing/shared everythin approach it is certainly true 
that shared nothing approach is better for hardware failures but it is 
also true that for shared nothing:

1) adding nodes to the cluster means repartiotioning (redistributing) 
datas on the nodes, how expensive (I mean CPU cylce cost...), difficult 
and errore prone is this operation for mysql cluster?
2) CPU processing power is not used optimally as in shared mode: single 
query operations are carried by different CPU based on data 
partition/availability on the different storage the CPU is linked to and no

I also wonder whether for really bug storage needs buying a shared disk 
array shared by some of the nodes could be cheaper than buying 
additional nodes with dedicated storage. One could use one shared 
storage for each n/x cluster nodes of n nodes cluster. This is clearly 
just an ecnonomic (€) consideration as ths system wouldn't affect 
performance at all.