Backing up and Importing IMAP folders

[Jerry]

On Thu, 20 Oct 2016 20:36:35 +0300, Konstantin Khomoutov stated:

>On Thu, 20 Oct 2016 16:57:45 +0300 (EEST)
>Aki Tuomi <aki.tuomi at dovecot.fi> wrote:
>
>[...]
>> > Alternatively you can use `dsync` to perform backup with a native
>> > Dovecot tool.  It's able to sync mailboxes of any Dovecot user --
>> > including synchronizing a mailbox to an empty (yet) spool.
>> > You'll need to do a bit of shell scripting which would spin around
>> > calling `doveadm user *` and feeding its output to something like
>> > 
>> >   while read user; do \
>> >     dest="/var/backup/dovecot/$user";
>> >     mkdir -p "$dest" && chown vmail:vmail "$dest" \
>> >       && chmod 0755 "$dest"
>> >     dsync -u "$user" backup "maildir:$dest" \
>> >   done
>> > 
>> > Note that you will only need this if you don't want to shut down
>> > Dovecot to copy its mail spool out.  
>> 
>> You can also use doveadm backup -A maildir:%u/  
>
>Could you please elaborate?
>
>I have a typical "virtual users" setup where I do have
>
>  mail_home = /var/local/mail/%Ln
>  mail_location = maildir:~/mail
>
>and everything is stored with uid=vmail / gid=vmail (much like
>described in the wiki, that is).
>
>I'd like to use a single call to `doveadm backup -A ...` to back up the
>whole /var/local/mail/* to another location
>(say, /var/backups/dovecot/) so that is has the same structure, just
>synchronized with the spool. (The purpose is to then backup the
>replica off-site).
>
>I tried to call
>
>  doveadm backup -A maildir:/var/backups/dovecot/%u
>
>and it created a directory "/var/backups/dovecot/%u" (with literal
>"%u", that is), created what appeared to be a single mailbox structure
>under it and after a while scared a heck out of me with a series of
>error messages reading
>
>dsync(user1): Error: Mailbox INBOX sync: mailbox_delete failed: INBOX
>can't be deleted.
>dsync(user2): Error: Mailbox INBOX sync: mailbox_delete failed: INBOX
>can't be deleted.
>...
>
>for each existing user.
>
>It appears that it luckily failed to delete anything in the source
>directory (though I have no idea what it actually tried to do).
>
>Reading the doveadm-backup(1) multiple times still failed to shed a
>light for me on how to actually backup the whole maildir hierarchy for
>all existing users.
>
>So, the question: how do I really should go about backing up the whole
>mailbox hierarchy in the case of virtual users?

I am experiencing the same problem as Konstantin. Is this s bug or
expected behavior.

-- 
Jerry