From: "Michael T. Babcock" <mbabcock@fibrespeed.net>
To: Nicholas Leippe <nick@byu.edu>
Cc: linux-raid@vger.kernel.org
Subject: Re: smart raid1 reads?
Date: Mon, 11 Aug 2003 14:27:23 -0400 [thread overview]
Message-ID: <3F37E00B.2000006@fibrespeed.net> (raw)
In-Reply-To: <200308111119.32344.nick@byu.edu>
Nicholas Leippe wrote:
>I don't know about the internals either, but it's already issuing block
>writes to both drives in parallel, I don't see why synchronization is an
>issue. Block layers don't usually care about serialization--that is left to the filesystem and higher os levels, no? If so, I would think it shouldn't matter--md1 is in effect here the new block layer--merging two other block devices into one--nothing should be bypassing that layer for any blocks in the partition it's using.
>
>
Part of what bothers me is that even without parallelizing for one large
read, if there are multiple queued reads from one RAID1 device that
aren't nearby (see elevator code), then read the second set from the
second drive, the third set from the first drive, and so on to minimize
head movement.
--
Michael T. Babcock
C.T.O., FibreSpeed Ltd.
http://www.fibrespeed.net/~mbabcock
next prev parent reply other threads:[~2003-08-11 18:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-08-11 12:32 smart raid1 reads? Michael T. Babcock
[not found] ` <200308111119.32344.nick@byu.edu>
2003-08-11 18:27 ` Michael T. Babcock [this message]
2003-08-13 2:06 ` Any mdadm based cgi perl script for webmin? Bo Moon
-- strict thread matches above, loose matches on Subject: below --
2003-06-20 1:14 smart raid1 reads? Nicholas Leippe
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