linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Bill Davidsen <davidsen@tmr.com>
To: Colin McCabe <colin.p.mccabe@gmail.com>
Cc: Tomasz Chmielewski <mangoo@wpkg.org>,
	Andrew Burgess <aab@cichlid.com>,
	linux-raid@vger.kernel.org
Subject: Re: unreadable drives can be synchronized?
Date: Wed, 23 May 2007 13:46:23 -0400	[thread overview]
Message-ID: <46547DEF.8040403@tmr.com> (raw)
In-Reply-To: <7296208f0705181118n32537ddck4d94bed08625b79f@mail.gmail.com>

Colin McCabe wrote:
> On 5/18/07, Tomasz Chmielewski <mangoo@wpkg.org> wrote:
>> Andrew Burgess schrieb:
>> >> Basically, B appears to be "write-only"; it will never return an 
>> error on a
>> >> write, but just try to read from it, and you will be sorry.
>> >
>> > It would be interesting to see what SMART says about drive B, 
>> especially
>> > the short and long self tests.
>>
>> I wouldn't rely on SMART.
>>
>> I have a broken drive, which has lots of badblocks - but SMART happily
>> claims it's fine (short/long tests are completed without errors).
>>
>
> If you haven't seen Google's hard drive study yet, you should take a 
> look.
> It's at http://labs.google.com/papers/disk_failures.pdf
>
> The conclusion says that "some of the SMART parameters are
> well-correlated with higher failure probabilities," but also that "a
> large fraction of [google's] failed drives have shown no SMART error
> signals whatsoever."
Having covered that in a presentation to a user group related to SMART. 
may I offer a paraphrase which may be more obvious to people who are not 
native speakers of English:

High counts of some SMART parameters indicate that the drive is likely 
to fail. However, most drives fail without warning.

-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979


  reply	other threads:[~2007-05-23 17:46 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-18 14:47 unreadable drives can be synchronized? Andrew Burgess
2007-05-18 15:04 ` Tomasz Chmielewski
2007-05-18 18:18   ` Colin McCabe
2007-05-23 17:46     ` Bill Davidsen [this message]
2007-05-18 18:10 ` Colin McCabe
  -- strict thread matches above, loose matches on Subject: below --
2007-05-16 15:50 Colin McCabe
2007-05-16 17:22 ` Bill Davidsen
2007-05-16 20:09   ` Colin McCabe
2007-05-16 20:18     ` Colin McCabe
2007-05-17  0:54 ` Neil Brown

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=46547DEF.8040403@tmr.com \
    --to=davidsen@tmr.com \
    --cc=aab@cichlid.com \
    --cc=colin.p.mccabe@gmail.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=mangoo@wpkg.org \
    /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).