Re: RAID0 performance question

["JaniD++" <djani22@dynamicweb.hu>]

----- Original Message ----- 
From: "Neil Brown" <neilb@suse.de>
To: "JaniD++" <djani22@dynamicweb.hu>
Cc: <linux-raid@vger.kernel.org>
Sent: Thursday, December 22, 2005 5:49 AM
Subject: Re: RAID0 performance question


> On Tuesday November 22, djani22@dynamicweb.hu wrote:
> > I have already try the all available options, including readahead in all
> > layer (result in earlyer mails), and chunksize.
> > But with this settings, i cannot workaround this.
> > And the result is incomprehensible for me!
> > The raid0 performance is not equal with one component , with sum of all
> > component , and not equal with the slowest component!
>
> This is quite perplexing.
>
> My next step would probably be to watch the network traffic with
> tcpdump or ethereal.  I would look for any differences between when it
> is going quickly (without raid0) and when slowly (with raid0).
>
> Rather than tcpdump, it might be easier to instrument the nbd server
> to print out requests and timestamps.

Yes, it is good idea!
I will try it, thanks!

>
> Sorry I cannot be more helpful, and do have a Merry Christmas anyway
> :-)

The same to you, and everybody on this list! :-)

Cheers,
Janos

>
> NeilBrown
> -
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