linux-raid.vger.kernel.org archive mirror
 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 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).