ZFS regimen: scrub, scrub, scrub and scrub again.

[Chris Rees]

On 23 Jan 2013 21:45, "Michel Talon" <talon at lpthe.jussieu.fr> wrote:
>
> On Wed, 23 Jan 2013 14:26:43 -0600, Chris Rees <utisoft at gmail.com> wrote:
>
> >
> > So we have to take your word for it?
> > Provide a link if you're going to make assertions, or they're no more
> > than
> > your own opinion.
>
> I've heard this same thing -- every vdev == 1 drive in performance. I've
> never seen any proof/papers on it though.
>
>
> first google answer from request "raids performance"
> https://blogs.oracle.com/roch/entry/when_to_and_not_to
>
> Effectively,  as  a first approximation,  an  N-disk RAID-Z group will
> behave as   a single   device in  terms  of  delivered    random input
> IOPS. Thus  a 10-disk group of devices  each capable of 200-IOPS, will
> globally act as a 200-IOPS capable RAID-Z group.  This is the price to
> pay to achieve proper data  protection without  the 2X block  overhead
> associated with mirroring.

Thanks for the link, but I could have done that;  I am attempting to
explain to Wojciech that his habit of making bold assertions and
arrogantly refusing to back them up makes for frustrating reading.

Chris