public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Timothy Miller <miller@techsource.com>
To: Mike Fedyk <mfedyk@matchmail.com>
Cc: Nick Piggin <piggin@cyberone.com.au>,
	Kyle Wong <kylewong@southa.com>,
	linux-kernel@vger.kernel.org
Subject: Re: questions about io scheduler
Date: Fri, 05 Mar 2004 18:49:49 -0500	[thread overview]
Message-ID: <4049121D.1060405@techsource.com> (raw)
In-Reply-To: <404905E1.70709@matchmail.com>



Mike Fedyk wrote:
> Nick Piggin wrote:
> 
>>
>>
>> Kyle Wong wrote:
>>
>>> 2. Does io scheduler works with md RAID? Correct me if I'm wrong,
>>> io-schedular <-->  md driver <--> harddisks.
>>>
>>>
>>
>> It goes md driver -> io schedulers -> hard disks.
> 
> 
> There is an IO scheduler per disk.
> 
> So MD submits the data to each disk through the IO scheduler.
> 
> This allows you to have the heads on each disk in the array at different 
> locations, and helps keep response times lower for seeky loads.

Say you've got a RAID1.  In this case, MD could send the read request to 
either device.  How does it decide which one to use?



  reply	other threads:[~2004-03-05 23:37 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-05  9:22 questions about io scheduler Kyle Wong
2004-03-05  9:20 ` Nick Piggin
2004-03-05 22:57   ` Mike Fedyk
2004-03-05 23:49     ` Timothy Miller [this message]
2004-03-05 23:58       ` Mike Fedyk
2004-03-05  9:20 ` Jens Axboe
     [not found] <1wjF1-2yG-19@gated-at.bofh.it>
     [not found] ` <1wk7X-31w-1@gated-at.bofh.it>
     [not found]   ` <1wwCd-Pi-5@gated-at.bofh.it>
     [not found]     ` <1wx5r-1qI-9@gated-at.bofh.it>
     [not found]       ` <1wxyd-1WX-1@gated-at.bofh.it>
2004-03-09 20:22         ` Bill Davidsen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4049121D.1060405@techsource.com \
    --to=miller@techsource.com \
    --cc=kylewong@southa.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mfedyk@matchmail.com \
    --cc=piggin@cyberone.com.au \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox