Backing up and Importing IMAP folders

[Jerry]

On Sat, 22 Oct 2016 05:16:07 -0400, Jerry stated:

>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 a bug or
>expected behavior.

Has anyone looked into this?