linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Greaves <david@dgreaves.com>
To: Neil Brown <neilb@cse.unsw.edu.au>
Cc: linux-raid@vger.kernel.org
Subject: Re: Spare disk could not sleep / standby
Date: Tue, 08 Mar 2005 08:51:58 +0000	[thread overview]
Message-ID: <422D67AE.1000506@dgreaves.com> (raw)
In-Reply-To: <16941.14813.465306.72004@cse.unsw.edu.au>

Neil Brown wrote:

>As the event count needs to be updated every time the superblock is
>modified, the event count will be updated forever active->clean or
>clean->active transition.  All the drives in an array must have the
>same value for the event count, so the spares need to be updated even
>though they, themselves, aren't exactly 'active' or 'clean'.
>  
>
May I ask why?
I can understand why the active drives need to have the same superblock 
- it marks the data set as consistent and is used on restart to indicate 
integrity across the set and avoid a resync.
But the spare has no data on it. What does it mean that the superblock 
is up to date?
In fact isn't that misleading?
Surely, if anything, the spare _should_ have an out of date superblock?

David



  parent reply	other threads:[~2005-03-08  8:51 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-03-08  4:05 Spare disk could not sleep / standby Peter Evertz
2005-03-08  4:14 ` Guy
2005-03-08  4:40   ` Neil Brown
2005-03-08  5:20     ` Molle Bestefich
2005-03-08  5:36       ` Neil Brown
2005-03-08  5:46         ` Molle Bestefich
2005-03-08  6:03           ` Neil Brown
2005-03-08  6:24             ` Molle Bestefich
     [not found]               ` <422D625C.5020803@medien.uni-weimar.de>
2005-03-08  8:57                 ` Molle Bestefich
2005-03-08 10:51                   ` Tobias Hofmann
2005-03-08 13:13                     ` Gordon Henderson
2005-03-09  5:11                       ` Brad Campbell
2005-03-09  9:03                       ` Tobias Hofmann
2005-03-08  8:51         ` David Greaves [this message]
2005-03-08 15:59     ` Mike Tran
2005-03-09 15:53     ` Spare disk could not sleep / standby [probably dangerous PATCH] Peter Evertz
2005-03-09 10:44       ` Mike Tran
2005-03-09 20:05         ` Peter Evertz
2005-03-09 16:29           ` Mike Tran
2005-03-09 23:20             ` Peter Evertz

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=422D67AE.1000506@dgreaves.com \
    --to=david@dgreaves.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=neilb@cse.unsw.edu.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;
as well as URLs for NNTP newsgroup(s).