Re: skip raid5 reconstruction

[Ming Zhang <mingz@ele.uri.edu>]

On Wed, 2005-07-06 at 10:47 +0400, Brad Campbell wrote:
> Ming Zhang wrote:
> > Hi folks
> > 
> > I am testing some HW performance with raid5 with 2.4.x kenrel.
> > 
> > It is really troublesome every time I create a raid5, wait 4 hours for
> > reconstruction, and then test some data and then recreate another one
> > and wait again. I wonder if there is any hack or option available to
> > create a raid5 without reconstruct the parity disk. I just have interest
> > to test the performance so do not care about data correctness at this
> > stage.
> 
> I did a similar thing a while back.
> I created the raid and waited for it to sync, I then make dd copies of the raid superblocks.
> When I blew it up I just dd the clean superblocks back again (saved a 12 hour rebuild time)
interesting to know about this. u just check the dmesg and see where is
the sb and then u dd it out and dd back later?


> 
> Having just thought about what you wrote, I guess you are building the raid in different
> configurationes each time, so my method might not be good for you.
> 
yes, i changed it many times.


thx anyway!


Ming



> Regards,
> Brad