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From: NeilBrown <neilb@suse.de>
To: Shaohua Li <shli@kernel.org>
Cc: linux-raid@vger.kernel.org
Subject: Re: [RFC 1/2]raid1: only write mismatch sectors in sync
Date: Thu, 18 Oct 2012 12:29:59 +1100	[thread overview]
Message-ID: <20121018122959.10bb6c87@notabene.brown> (raw)
In-Reply-To: <20121018011735.GA1448@kernel.org>

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On Thu, 18 Oct 2012 09:17:35 +0800 Shaohua Li <shli@kernel.org> wrote:
 
> > > Neil,
> > > any further comments on this? This is a usable feature, I hope we can have some
> > > agreements.
> > 
> > You still haven't answered my main question, which possibly means I haven't
> > asked it very clearly.
> > 
> > You are saying that this new behaviour should not be the default and I think
> > I agree.
> > So the question is:  how it is selected?
> > 
> > You cannot expect the user to explicitly enable it any time a resync or
> > recovery starts that should use this new feature.  You must have some
> > automatic, or semi-automatic, way for the feature to be activated, otherwise
> > it will never be used.
> > 
> > I'm not asking "when should the feature be used" - you've answered that
> > question a few time and it really isn't an issue.
> > The question it "What it the exact process by which the feature is turned on
> > for any particular resync or recovery?"
> 
> So you worried about users don't know how to correctly select the feature. An
> experienced user knows this, the usage scenario I mentioned describes how to do
> the decision. For example, a resync after system crash should enable the
> feature. I admit an inexperienced user doesn't know how to select it, but this
> isn't a big problem to me. There are a lot of tunables in the kernel (even MD),
> which can significantly impact kernel behavior. These tunables are just for
> experienced users.
> 
> Thanks,
> Shaohua


You still aren't answering my question.

What exactly, precisely, specifically, will an "experienced user" do?

NeilBrown

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  reply	other threads:[~2012-10-18  1:29 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-26  8:01 [RFC 1/2]raid1: only write mismatch sectors in sync Shaohua Li
2012-07-27 16:01 ` Jan Ceuleers
2012-07-30  0:39   ` Shaohua Li
2012-07-30  1:07     ` Roberto Spadim
2012-07-31  5:53 ` NeilBrown
2012-07-31  8:12   ` Shaohua Li
2012-09-11  0:59     ` NeilBrown
2012-09-12  5:29       ` Shaohua Li
2012-09-18  4:57         ` NeilBrown
2012-09-19  5:51           ` Shaohua Li
2012-09-19  7:16             ` NeilBrown
2012-09-20  1:56               ` Shaohua Li
2012-10-17  5:11                 ` Shaohua Li
2012-10-17 22:56                   ` NeilBrown
2012-10-18  1:17                     ` Shaohua Li
2012-10-18  1:29                       ` NeilBrown [this message]
2012-10-18  2:01                         ` Shaohua Li
2012-10-18  2:36                           ` NeilBrown
2012-10-21 17:14                             ` Michael Tokarev
2012-10-31  3:25                             ` Shaohua Li
2012-10-31  5:43                               ` NeilBrown
2012-10-31  6:05                                 ` Shaohua Li
2012-10-18  1:30                       ` kedacomkernel
2012-11-20 17:00                     ` Joseph Glanville

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