linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ian Pilcher <arequipeno@gmail.com>
To: NeilBrown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: Inoperative array shown as "active"
Date: Sat, 14 Sep 2013 01:25:11 -0500	[thread overview]
Message-ID: <52340147.9090600@gmail.com> (raw)
In-Reply-To: <20130914155912.5ba135d9@notabene.brown>

On 09/14/2013 12:59 AM, NeilBrown wrote:
> On Sat, 14 Sep 2013 00:39:20 -0500 Ian Pilcher <arequipeno@gmail.com> wrote:
>> AFAICT, this means that there is no single item in either /proc/mdstat
>> or sysfs that indicates that an array such as the example above has
>> failed.  My program will have to parse the RAID level, calculated the
>> number of failed members (if any), and determine whether that RAID level
>> can survive that number of failures.  Is this correct?
> 
> Yes.
> 
>>
>> Anything I'm missing?
> 
> mdadm already does this for you. "mdadm --detail /dev/md0".
> 

Yeah, I haven't yet ruled out calling out to mdadm.  I'm already doing
that with hddtemp and smartctl.  It just seems a bit inefficient to do
so when all of the information is sitting right there in /proc/mdstat.

A quick test reveals that running "mdadm --detail /dev/md?*" takes
around 2 seconds on the NAS and produces about 20KB of output.  (I have
20 RAID devices -- hooray GPT! -- and an Atom processor.)  Hmmm.

Thanks for the very quick response!

-- 
========================================================================
Ian Pilcher                                         arequipeno@gmail.com
Sometimes there's nothing left to do but crash and burn...or die trying.
========================================================================

      reply	other threads:[~2013-09-14  6:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-09-14  5:39 Inoperative array shown as "active" Ian Pilcher
2013-09-14  5:59 ` NeilBrown
2013-09-14  6:25   ` Ian Pilcher [this message]

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=52340147.9090600@gmail.com \
    --to=arequipeno@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).