linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Anssi Hannula <anssi.hannula@gmail.com>
To: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: Recovery speed at 1MB/s/device, unable to change
Date: Mon, 24 Apr 2006 01:48:39 +0300	[thread overview]
Message-ID: <444C0447.4040200@gmail.com> (raw)
In-Reply-To: <17483.63636.745420.456281@cse.unsw.edu.au>

(sorry, prev post missed the list)

Neil Brown wrote:
> On Monday April 24, anssi.hannula@gmail.com wrote:
> 
>># mdadm --grow /dev/md_d1 --raid-devices=3 --backup-file backupfile
>>mdadm: Need to backup 128K of critical section..
>>mdadm: /dev/md_d1: Cannot get array details from sysfs
>>
>>Strace shows that it's trying to access
>>"/sys/block/md_d4/md/component_size".
>>
>>Why is this?
> 
> 
> Because I didn't test my code properly :-(
> 
> Following patch should fix it.

Okay, will test.

> Re: the recovery speed problem:  I would try dding from one drive to
> the other and see what sort of speed you get then:
>   dd if=/dev/sda of=/dev/sdb bs=1024k count=1000
> or something like that.


# export LANGUAGE=C; export LANG=C; export LC_ALL=C; date; dd
if=/dev/sda skip=20000 of=/dev/sdb bs=1024k count=1000; date
Mon Apr 24 01:14:48 EEST 2006
1000+0 records in
1000+0 records out
Mon Apr 24 01:15:42 EEST 2006

So the speed is about 20MB/s.

-- 
Anssi Hannula



  reply	other threads:[~2006-04-23 22:48 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-04-23 19:22 Recovery speed at 1MB/s/device, unable to change Anssi Hannula
2006-04-23 21:37 ` Anssi Hannula
2006-04-23 21:58   ` Neil Brown
2006-04-23 22:48     ` Anssi Hannula [this message]
2006-04-23 22:49     ` Anssi Hannula
2006-04-24 13:33       ` Anssi Hannula

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=444C0447.4040200@gmail.com \
    --to=anssi.hannula@gmail.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=neilb@suse.de \
    /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;
as well as URLs for NNTP newsgroup(s).