From: Neil Brown <neilb@suse.de>
To: hank peng <pengxihan@gmail.com>
Cc: Michael Evans <mjevans1983@gmail.com>,
linux-raid <linux-raid@vger.kernel.org>
Subject: Re: about raid5 recovery when created
Date: Thu, 10 Dec 2009 12:43:59 +1100 [thread overview]
Message-ID: <20091210124359.4dd1a93a@notabene.brown> (raw)
In-Reply-To: <389deec70912090329w65b7fa06hff8b75ad8f637307@mail.gmail.com>
On Wed, 9 Dec 2009 19:29:04 +0800
hank peng <pengxihan@gmail.com> wrote:
> I think it is better to implement this function in kernel's md layer.
> I wonder what Neil Brown think of this?
I don't think it is worth the effort.
You probably would save some CPU time as you don't need to XOR, but as has
been said, we are usually IO bound, not CPU bound.
With the current arrangement, you can start using the array immediately - you
don't have to wait for the initial recovery to complete.
If you zeroed all devices at create time, you would have to wait for that to
complete before using the array.
So I see very little gain, and significant cost.
NeilBrown
next prev parent reply other threads:[~2009-12-10 1:43 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-08 13:01 about raid5 recovery when created hank peng
2009-12-08 13:14 ` Robin Hill
2009-12-08 13:49 ` hank peng
2009-12-08 13:56 ` Robin Hill
2009-12-08 14:03 ` hank peng
2009-12-09 8:30 ` Michael Evans
2009-12-09 11:29 ` hank peng
2009-12-10 1:43 ` Neil Brown [this message]
2009-12-10 3:34 ` Michael Evans
2009-12-10 3:59 ` Neil Brown
[not found] ` <g3143w7eigolu0x2ziUYAxe124vaj_firegpg@mail.gmail.com>
2009-12-30 2:55 ` Neil Brown
[not found] ` <389deec70912090330l73d04696v1d23dbe74423d15b@mail.gmail.com>
2009-12-09 23:29 ` Michael Evans
2009-12-08 13:52 ` hank peng
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