Re: [gentoo-user] Raid 5 creation is slow - Can this be done quicker? [SOLVED]

["J. Roeleveld" <joost@antarean.org>]

On Monday 01 February 2010 12:58:49 J. Roeleveld wrote:
> Hi All,
> 
> I am currently installing a new server and am using Linux software raid to
> merge 6 * 1.5TB drives in a RAID5 configuration.
> 
> Creating the RAID5 takes over 20 hours (according to " cat /proc/mdstat ")
> 
> Is there a way that will speed this up? The drives are new, but contain
>  random data left over from some speed and reliability tests I did. I don't
>  care about keeping the current 'data', as long as when the array is
>  reliable later.
> 
> Can I use the " --assume-clean " option with mdadm and then expect it to
>  keep working, even through reboots?
> Or is this a really bad idea?
> 
> Many thanks,
> 
> Joost Roeleveld
> 

Hi all,

Many thanks for all the input, I did wait the 20 hours, but when it was 
finished, the performance was still slow. And trying out different options for 
the array didn't actually help.

Thanks to the thread "1-Terabyte drives - 4K sector sizes? -> bar performance 
so far" I figured out the problem (4KB sectors).
After changing the partitions to use sector 64 as start (as opposed to 63) a 
build of the array should only take 6 hours.
Hopefully, the raid-array will also show a better performance when this is 
finished.

--
Joost Roeleveld