Re: RAID stride size (stripe) and Oracle block size

Neil Greene replace dev.null with laoc.SHL.com wrote:
>
> Eugene Gardner wrote....
> > > On our new RAIDs the stride size (stripe) is 64 KB. What PROVEN
> > > recommendations would you have about what to set the Oracle blocksize to
> > > in relation to the stride size.
> > Shouldn't you get the optimum Oracle block size from the average
> > amount of data which the server is asked for. Then use that to set
> > your stripe (chunk) size.
>
> You want your OBS to be a multiple of your OS block size. Pros and cons of
> which block size to use removed.
>
> Now, you want your DB_FILE_MULTIBLOCK_READ_COUNT to be an even multiple of
> your stripe size. --- Neil
>
> --
> Neil Greene Senior System Engineer / Oracle DBA
> MCI Systemhouse, Inc.
>
> Email: <mailto:ngreene_at_laoc.SHL.com>
> Pager Email: 4112636_at_PageMCI.com Pager: 800-411-2636

Hi,

be aware of the following:
In NT 64K can be read at once. with a block-size of 8k you should be able to read 8 blocks at once. But you can't. Oracle needs a supplement of about 500 Bytes for administration so that you can read (64K-500Bytes) Mod 8K = 7 blocks at once.

-- 
Regards

M.Gresz    :-)