On Fri, Jun 13, 2008 at 09:08:48AM +0200, Wojciech Puchar wrote:
> >>Does gstripe read an entire stripe at a time?  If so, why do that instead 
> >>of
> >>just reading a few requested blocks?  If not, then is there any advantage
> >>to large stripes?
> >
> >Apparently it won't read anything larger than your stripe size which 
> >defaults to a miserable 4k.
> 
> 
> depending from what's needed, but unless i need just huge linear transfer, 
> i set stripe size to something huge, like 256MB.
> 
> then single read is rarely split on 2 disks, while multiple reads have 
> good chances to touch different drives

Come to think of it I didn't try setting the stripe size larger than the
ATA max transaction size of 128k.

Still, I don't understand what is going on when I use md5(1) on a
gigabyte file hosted on a gstripe partition with 128k stripes that
"systat -v" reports transactions are usually between 42k and 43k each?

On a non-striped filesystem the same operation runs 126k to 127k
transfers.

Transfer bandwidth seems to be limited by the number of transactions per
second more than the size of the transaction.

-- 
David Kelly N4HHE, [EMAIL PROTECTED]
========================================================================
Whom computers would destroy, they must first drive mad.
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