Re: striping (RAID0) performance ?

Chris Atenasio (root@lilo.dyn.ml.org)
Mon, 22 Jun 1998 21:25:57 -0500 (EST)


On Fri, 19 Jun 1998, Davide Rossetti wrote:
> Could someone explain to me why aren't they so exciting ?
Well what excites me about RAID is the speed in random access. Different
disks can seek to different places at the same time making me happy. It
has taken the compiling bottleneck off my poor drives and put on my ppros
where it should be. BTW for timing sequential access I simply
do a:

hdparm -t /dev/sda

and compare that to

hdparm -t /dev/md0

It's almost x2 here.

>
> It seems that the md driver is only remapping sectors, not using any
> I/O overlapping. this way the performance gain is marginal.
With sequential access the could very well be true. But then again what
real life activity just makes a big file full of zeroes? :)

- Chris
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Chris Atenasio (chrisa@ultranet.com) -- Friends dont let friends use Windows.
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