Strange subscriptions added by dsync backup

[Rik Theys]

Hi,

We're in the process of migrating our dovecot 1.x mail server to a
Dovecot 2.2.25 server. During the migration I'm moving from mbox storage
to mdbox.

I use the following method to do a one-way sync from our current mail
server to our new mail server (command executed on the new server):

doveadm -v -o imapc_host=oldserver \
        -o imapc_user=$u \
        -o imapc_master_user=$masteruser \
        -o imapc_password="$masterpass" \
        -o imapc_port=993 -o imapc_ssl=imaps \
        -o ssl_client_ca_file=/etc/pki/tls/certs/ca-bundle.crt \
        -o imapc_ssl_verify=yes \
        -o mail_fsync=never \
        -o mail_prefetch_count=20 \
        backup -R -u $u imapc:


$u is replaced by the username I'm migrating.

The dsync command runs and exits with code 0 (all OK).

However, when I look at the subscriptions file on the new server, there
seem to be additional subscriptions that are not in the subscriptions
file on the old server:

7b0d681945d0fc5711560000ffff90ca
7c0d681945d0fc5711560000ffff90ca
7d0d681945d0fc5711560000ffff90ca
7e0d681945d0fc5711560000ffff90ca
7f0d681945d0fc5711560000ffff90ca
800d681945d0fc5711560000ffff90ca

Where do these come from? Is something wrong with the migration?

It also seems that subscriptions for IMAP folders that only contain
subfolders[1] are no longer present in the new subscriptions file:

# diff -u sub-old.sorted sub-new.sorted
--- sub-old.sorted    2016-10-11 13:42:44.175070610 +0200
+++ sub-new.sorted    2016-10-11 13:47:53.973888462 +0200
@@ -1,26 +1,26 @@
-Archive/Administration/
+7b0d681945d0fc5711560000ffff90ca
+7c0d681945d0fc5711560000ffff90ca
+7d0d681945d0fc5711560000ffff90ca
+7e0d681945d0fc5711560000ffff90ca
+7f0d681945d0fc5711560000ffff90ca
+800d681945d0fc5711560000ffff90ca
 Archive/Administration/Conferences
 Archive/Announcements
-Archive/Education/
 Archive/Education/E02N3A
 Archive/Education/I0D51A
 Archive/Politics
-Archive/Research/
-Archive/Research/FET/
 Archive/Research/FET/VPH - Virtual Physiological Human
 Archive/Research/Grants/ICON IBBT Call 2011
 Archive/Research/Grants/Marie Curie ITN 2011
 Archive/Research/Grants/Odysseus
 Archive/Research/Grants/SymBioSysII/Funding
 Archive/Research/Grants/SymBioSysII/JobApplications
-Archive/Research/Manuscripts/
 Archive/Research/Manuscripts/ruby-ensembl-api
 Archive/Research/Projects/GUNZ
 Archive/Research/Projects/MIQAS
 Archive/Research/Projects/MODY
 Archive/Research/Projects/ruby-ensembl-api
 Archives
-Archive/Service/
 Archive/Service/EditorORC
 Archive/Service/Reviewing
 Deleted Messages

Is this expected behaviour?

Regards,

Rik

[1] On the old server a folder can only contain either messages or
subfolders, not both at the same time.

-- 
Rik Theys
System Engineer
KU Leuven - Dept. Elektrotechniek (ESAT)
Kasteelpark Arenberg 10 bus 2440  - B-3001 Leuven-Heverlee
+32(0)16/32.11.07
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