[Dovecot] Mbox corruption - Inbox beginning with 'FFrom' or 'FrFrom'

[Erik Kratzenberg]

We've had situations where the same user will have their mailbox 
corrupted 2 or 3 times a day.

We're not using filesystem quotas and nothing but Dovecot is writing to 
these mailboxes.

We've been pushing people to switch to IMAP which seems to be the only 
solution so far.  That's decreased the number of reports we're getting, 
but they're definitely still coming in.

On 05/25/10 15:10, Timo Sirainen wrote:
> On Fri, 2010-05-07 at 15:03 -0400, Erik Kratzenberg wrote:
>>>>>>       -Dovecot.log : Mar 29 11:00:06 Error: POP3(user_login):
>>>>    >   >          Couldn't init INBOX: Mailbox isn't a valid mbox
>>>>    >   >       -The mailbox start with either 'FFrom or 'FrFrom'
>> It's happening several times a day, sometimes to the same mailbox.
>
> How often does the same user get the error?
>
>> We also noticed some other storage and assertion errors around the same
>> time the corruption occurs which may or may not be related:
>>
>> Mar 26 14:49:36 dovecot: Panic: POP3(user at home.com):
>> file mbox-sync.c: line 1314 (mbox_sync_handle_eof_updates): assertion
>> failed: (offset == 0|| offset>  31)
>
> There's a good chance this is related.
>
>> Mar 24 15:21:59 dovecot: POP3(user at home.com): Cached
>> message offset 2 is invalid for mbox file
>> /usr/boxes/mailbox
>
> Are you using filesystem quota for users? That might explain this.
> Otherwise, the above shouldn't be happening if Dovecot is the only
> software writing to the mbox files..
>
>> I'm not sure if "mail_debug=yes" will give us any additional info, but
>> I'm turning that on now.
>
> No, that won't log anything useful.
>