[Dovecot] Mbox corruption

[Erinn Looney-Triggs]

On 12/07/2009 11:41 AM, Timo Sirainen wrote:
> On Mon, 2009-12-07 at 08:29 -0700, Erinn Looney-Triggs wrote:
>> I am trying to track down an mbox corruption issue that has been
>> happening for one of our users. It appears that the mbox file is getting
>> truncated and the all important From line no longer exists which then
>> leads to the mbox being useless. It also appears, as in most
>> truncations, that parts of the mbox are being lost.
>
> Can you give me some specific examples of what the corruption looks
> like? For example you could put the mbox through
> http://dovecot.org/tools/mbox-anonymize.pl
>
>> I am not sure how to
>> debug this to find out whether this is a client or server issue and any
>> pointers would be appreciated.
>
> Client can't corrupt mailbox data no matter what they do. But it's
> possible that the user/client is doing something a bit differently than
> everyone else and that causes it.
>
> What OS and filesystem do you use? It's a local filesystem and not NFS
> or something? Does Dovecot log any errors (about anything)?

I can dig up a copy of a malformed mbox and I will get it to you. As for 
the other details This is a RHEL5 x64 system running an ext3 file 
system, nothing fancy with NFS. Dovecot does not appear to log any 
errors, I looked back and there was one error logged a couple of days 
before the issue occurred but I am not sure if it is related:

Dec  2 11:19:07  dovecot: IMAP(XXXX): Next message unexpectedly lost 
from mbox file /home/XXXX/mail/Sent at 2102537 (cached)
Dec  2 11:19:07  dovecot: IMAP(XXXX): read(mail, uid=501) failed: 
Invalid argument
Dec  2 11:19:07  dovecot: IMAP(XXXX): Disconnected: Internal error 
occurred. Refer to server log for more information. [2009-12-02 
11:19:07] bytes=177474/43685174

But as I said this occurred a couple of days before the corruption 
issue, or at least before the user became aware of the corruption, 
though this user is connected all day every day.


Anyway I will dig around for a copy of the corrupted mbox files.

Thanks,
-Erinn