Re: Element Size - RAID 10 SAN

Hello Art, big writes are 16 pages. haven't checked out when the pagesize is 32k yet... i would use chunks which are twice 16 pages to avoid split writes. Superboer. Art S. Kagel schreef: > Tam O'Shanter wrote: > > Wondering about the optimal configuration for a Raid 10 array, specifically, > > element/block/stripe sizes. > > > > Does this relate to my DB block size the same way it would with Oracle? > > > > Given the smaller the element size, the more efficient the distribution of > > data written, and that most writing logic will write to the same stripe > > multiple times if more than one page will fit (again, much more efficient) > > where do I find the happy medium? > > Unlike setting up an array for a filesystem, you want to keep the stripe > block size fairly small. IDS always writes either a single page or a 'big > block' of eight pages. You definitely want to minimize the number of times > that an array block is written to and increase the chances that cache gather > operations will be able to combine writes as often as possible. For a 2K > pagesize I like 16 or 32K blocks and I think that would work for 4K & 8K > pagesizes just as well if not better. For larger pagesized I'd want to > experiment with increasing that a bit, but I haven't tried it. > > Art S. Kagel