I’m trying backup a user’s IMAP folders from a system running dovecot 2.1.7. to
a system running dovecot 2.3.19.1. After much perusing of the web and Dovecot
documentation I tried this:
1) On the 2.1.7 host set up the doveadm server to listen on TCP port 2425
and defined a doveadm_password value
2) Issued the following command on the 2.13.19.1 system:
doveadm -o doveadm_password=<password> backup -R -u <username> -S
<host>:2425 tcp:<host>
3) The command returned the following errors:
Error: doveadm server disconnected before handshake: EOF
Error: Command backup failed for <username>: EOF
4) In the Dovecot log on the 2.1.7 system I found the following error
message:
dsync(<username>): Error: user <username>: Initialization failed:
Namespace '': Unknown mail storage driver tcp
dovecot: dsync(<username>): Fatal: User init failed
A couple of questions:
1) I thought that setting up doveadm-server as an inet_listener (with a
password) meant that all communications (including the backup) occurred over
that link - is that not correct?
Or does SSH also need to be enabled as well?
2) Am I specifying the arguments correctly? The definition of the
destination argument is confusing in the documentation - if doveadm is trying
to backup a user’s IMAP mailboxes from a remote source, and you’ve already
specified the information needed to connect to the remote sources
doveadm-server why would the source need to be specified again via the TCP:
argument?
