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On 15/07/2019 09:00 Mike via dovecot <
<a href="mailto:dovecot@dovecot.org">dovecot@dovecot.org</a>> wrote:
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Hello,
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I was forced to do an emergency server migration with about 3000
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mailboxes and I botched it somewhat. Hoping to find some help here.
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My symptoms are, users showing apparently deleted mail messages, some
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replicated mail, and a time period of mail that is just 'missing'.
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The source server is centos 6.10 with dovecot 2.2.5, and the destination
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is ubuntu 16 / dovecot 2.2.22. User mailboxes are mdbox format and I did
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an rsync from the old to the new. My screw up however was that my rsync
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was not --delete files, and had to be run multiple times over the course
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of a few weeks due to to bandwidth disparities and the sheer size of the
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mail spool approaching 700GB (source server had 10mbps. Should have used
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sneakernet instead). The bottom line however is that I wound up having
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many extra m.* files in each user storage dir that were not actually
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present on the source when the final, final sync was made and I went
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live with the migration server. I know this is my fsckup but now I have
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to deal with it.
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I first tried to fix the symptoms with a force-resync on the boxes not
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realizing the above, and that seemed to make things worse by only
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showing new mail as of the server migration date. Ugh.
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New mail is being delivered and this does appear in user mail boxes. But
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as I said, there seems to be some users with a problem with old mail
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presumably deleted on the prior server suddenly re-appearing (probbly
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due to the extraneous m.* mdbox files present). A more pressing problem
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is that there is simply a time period of mail that is in user mailboxes
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(on the old server) from before the migration, which is not displaying
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now for these users on the new server.
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I have investigated this and hacked on "mdbox-recover.pl" somewhat so
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that it iterates over all mdbox files for a user and I can extract ALL
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messages, and see that, yes, the mail really is present in the mdbox
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files, but pop/imap never shows it. This is puzzling to me. I have a
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test user that when I check imap, it shows only 21 message in inbox and
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1 in sent. But if I extract the messages from the mdbox files, then I
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actually have 1117 messages.
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I know I can't just rsync the source server again with the right
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--delete flag, there has been lots of mail deliveries to the migrated
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boxes and so I don't want to lose all of that and create yet more
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problems. But I need to find some way to make these present mail
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messages appear for my users again. Im thinking it's got to be a flag of
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some kind since the data is there it's just ignored. Wondering what you
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would reccomend?
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Thanks.
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Mike-
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Try with one mailbox first.
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Delete dovecot.index.map files and run force-resync.
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<pre>---
Aki Tuomi</pre>
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