All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Theodore Ts'o" <tytso@mit.edu>
To: Shradha Gupta <shradhagupta@linux.microsoft.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [BUG]:OS disk corruption EXT4
Date: Wed, 27 Apr 2022 10:34:25 -0400	[thread overview]
Message-ID: <YmlUcTn4x91HYTVK@mit.edu> (raw)
In-Reply-To: <20220427043946.GA21120@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net>

On Tue, Apr 26, 2022 at 09:39:46PM -0700, Shradha Gupta wrote:
> I think I may have run into an issue where my ext4 OS disk shows
> multiple corruptions and the issue is reproducible after multiple
> reboots.
> 
> Please help me understand this corruption better as I am new to ext4 layouts. 
> 
> The “fsck -n <device>” command output was as follows:
> 
> e2fsck 1.45.5 (07-Jan-2020)
> ext2fs_open2: Superblock checksum does not match superblock
> fsck.ext4: Superblock invalid, trying backup blocks...
>  Superblock needs_recovery flag is clear, but journal has data.
> Recovery flag not set in backup superblock, so running journal anyway.

You need to give more information; what kernel version are you using?

What is the hardware or cloud VM configuration that you are using?

How are you rebooting the machine?  Are you doing a clean shutdown, or
are you just kicking the plug out of the wall, or killing the VM
without giving a chance for the system to shut down cleanly?

Ext4 should handle an unclean shutdown cleanly, assuming that the
hardware (or emulated disk, in the case of a cloud system) properly
handles CACHE FLUSH requests.

Given the vaguely suggested label on your file system...

> cloudimg-rootfs was not cleanly unmounted, check forced.

Is there anything special going on --- in particular, is this part of
creating a cloud image?  If so, are you doing anything "interesting",
such as updating the Label or UUID using tune2fs racing with, say, an
online resize, or an uncerimonious VM shutdown?

If it is reproducible, can you give us the reproduction recipe?

Thanks,

					- Ted

      reply	other threads:[~2022-04-27 14:34 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-27  4:39 [BUG]:OS disk corruption EXT4 Shradha Gupta
2022-04-27 14:34 ` Theodore Ts'o [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=YmlUcTn4x91HYTVK@mit.edu \
    --to=tytso@mit.edu \
    --cc=linux-ext4@vger.kernel.org \
    --cc=shradhagupta@linux.microsoft.com \
    /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.