All of lore.kernel.org
 help / color / mirror / Atom feed
From: Josh Litherland <josh@temp123.org>
To: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Subject: Re: Superblock checksum problems
Date: Mon, 04 Sep 2006 16:55:47 -0400	[thread overview]
Message-ID: <1157403347.2990.11.camel@localhost> (raw)
In-Reply-To: <1157385612.2990.4.camel@localhost>

On Mon, 2006-09-04 at 12:00 -0400, Josh Litherland wrote:

> I'll test to see if they actually change values, but I can say for
> certain that they are still invalid checksum, i.e. once I stop the array
> I have to assemble it with -U resync to get it back online. (and it of
> course rebuilds)

Some real strangeness here... So, while the array was up and running
(after mdadm -A -f -U resync ...) I checked the checksums:

       Checksum : 70c30de5 - expected 70c30db5
       Checksum : 70c30df7 - expected 70c30dd7
       Checksum : 70c30e09 - expected 70c30de9
       Checksum : 70c30e1b - expected 70c30deb

Then I unmounted, checked again... here's where things get weird

       Checksum : 70c352e8 - correct
       Checksum : 70c352fa - expected 70c352da
       Checksum : 70c3530c - expected 70c352ec
       Checksum : 70c3531e - correct

Went ahead and issues mdadm -S

       Checksum : 70c352e8 - expected 70c352c8
       Checksum : 70c352fa - expected 70c352da
       Checksum : 70c3530c - expected 70c352ec
       Checksum : 70c3531e - expected 70c352fe

Now utterly perplexed, I went ahead and checked mdadm -E several more
times.  The actual stored checksum value isn't changing, but it's
switching around to saying "expected <something else>" to saying
"correct"... on ALL 4 drives at different times.

Anybody have a clue what's going on here?  How does mdadm (or the
kernel, for that matter) decide what the checksum SHOULD be?  I'll
code-dive to see if I can answer that myself, but if anyones knows,  I'd
appreaciate a pointer.

Thanks!

-- 
Josh Litherland (josh@temp123.org)


  reply	other threads:[~2006-09-04 20:55 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-02 22:36 Superblock checksum problems Josh Litherland
2006-09-04  5:12 ` Neil Brown
2006-09-04 16:00   ` Josh Litherland
2006-09-04 20:55     ` Josh Litherland [this message]
2006-09-04 21:13       ` Josh Litherland
2006-09-04 21:35         ` Neil Brown
2006-09-04 21:46           ` Josh Litherland
2006-09-04 23:11             ` Josh Litherland
2006-09-04 23:17               ` Neil Brown
2006-09-04 23:43               ` Henrik Holst
2006-09-06  7:07                 ` Mario 'BitKoenig' Holbe
2006-09-06 13:26               ` Josh Litherland
2006-09-07 20:40                 ` Josh Litherland
2006-09-04 21:54           ` Josh Litherland

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=1157403347.2990.11.camel@localhost \
    --to=josh@temp123.org \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.