dovecot - Jun 2012 - dsync error: "Mailboxes don't have unique GUIDs"

I'm getting an error backing up mailboxes. I'm using the mirror
command:

dsync -fvo mail_home=/home/users/bob mirror ssh vmail at 10.1.4.1 dsync -o
mail_home=/home/.incoming_mail_migrations/users/bob

dsync-remote(vmail): Error: Mailboxes don't have unique GUIDs:
1ef6ee37c694894d783100000581a675 is shared by INBOX and INBOX
dsync-remote(vmail): Error: command BOX-LIST failed
dsync-local(vmail): Error: Worker server's mailbox iteration failed

	The mail user doesn't yet exist on the destination yet, thus the use of
the mail_home parameter.
	I found a mailing list message where a person was having a similar
problem but I couldn't find confirmation that the issue was resolved.
	In our case, the backup goes from maildir to mdbox format (we can't to
convert to mdbox). Things seemed to be moving along, but there are quite
a few examples of dsync failing. I think the issue happens more often
with large mailboxes ( > 50GB ). 
	We're running version 2.0.13. 
	doveconf -n:

# 2.0.13: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.18-274.12.1.el5 x86_64 CentOS release 5.7 (Final) 
auth_mechanisms = plain login
default_client_limit = 15000
default_process_limit = 10000
disable_plaintext_auth = no
listen = *
mail_gid = vmail
mail_location = maildir:~/Maildir
mail_plugins = zlib
mail_uid = vmail
mmap_disable = yes
namespace {
  inbox = yes
  location = 
  prefix = INBOX.
  separator = .
}
passdb {
  args = /etc/dovecot/conf.d/dovecot-sql.conf.ext
  driver = sql
}
plugin {
  zlib_save = gz
}
protocols = imap pop3
service auth {
  client_limit = 10000
  unix_listener auth-userdb {
    mode = 0666
  }
}
service imap-postlogin {
  executable = script-login /usr/bin/postlogin-imap.sh
  user = $default_internal_user
}
service imap {
  drop_priv_before_exec = yes
  executable = imap
  process_limit = 10000
}
service pop3-postlogin {
  executable = script-login /usr/bin/postlogin-pop.sh
  user = $default_internal_user
}
}
service pop3 {
  drop_priv_before_exec = yes
  executable = pop3
  process_limit = 2500
}
ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
ssl_key = </etc/pki/dovecot/private/dovecot.pem
userdb {
  driver = prefetch
}
userdb {
  args = /etc/dovecot/conf.d/dovecot-sql.conf.ext
  driver = sql
}
protocol lmtp {
  mail_plugins = zlib
}
protocol lda {
  mail_plugins = zlib
}
protocol imap {
  mail_max_userip_connections = 100
  mail_plugins = zlib
}
protocol pop3 {
  mail_max_userip_connections = 30
  mail_plugins = zlib
}


...Jeff

Hey, just a point of clarification.

In at least some of the cases (possibly all, I'll leave that up to Jeff to
state) an initial dsync (as documented in Jeff's message) was completed
successfully and the problem occurred when we ran a second (using exactly the
same cmd) time to catch any changes since the original sync (since the initial
sync took many hours).

Doug

On Jun 22, 2012, at 2:24 PM, Jeff Gustafson wrote:
> 	I'm getting an error backing up mailboxes. I'm using the mirror
> command:
> 
> dsync -fvo mail_home=/home/users/bob mirror ssh vmail at 10.1.4.1 dsync -o
> mail_home=/home/.incoming_mail_migrations/users/bob
> 
> dsync-remote(vmail): Error: Mailboxes don't have unique GUIDs:
> 1ef6ee37c694894d783100000581a675 is shared by INBOX and INBOX
> dsync-remote(vmail): Error: command BOX-LIST failed
> dsync-local(vmail): Error: Worker server's mailbox iteration failed
> 
> 	The mail user doesn't yet exist on the destination yet, thus the use
of
> the mail_home parameter.
> 	I found a mailing list message where a person was having a similar
> problem but I couldn't find confirmation that the issue was resolved.
> 	In our case, the backup goes from maildir to mdbox format (we can't to
> convert to mdbox). Things seemed to be moving along, but there are quite
> a few examples of dsync failing. I think the issue happens more often
> with large mailboxes ( > 50GB ). 
> 	We're running version 2.0.13. 
> 	doveconf -n:
> 
> # 2.0.13: /etc/dovecot/dovecot.conf
> # OS: Linux 2.6.18-274.12.1.el5 x86_64 CentOS release 5.7 (Final) 
> auth_mechanisms = plain login
> default_client_limit = 15000
> default_process_limit = 10000
> disable_plaintext_auth = no
> listen = *
> mail_gid = vmail
> mail_location = maildir:~/Maildir
> mail_plugins = zlib
> mail_uid = vmail
> mmap_disable = yes
> namespace {
>  inbox = yes
>  location = 
>  prefix = INBOX.
>  separator = .
> }
> passdb {
>  args = /etc/dovecot/conf.d/dovecot-sql.conf.ext
>  driver = sql
> }
> plugin {
>  zlib_save = gz
> }
> protocols = imap pop3
> service auth {
>  client_limit = 10000
>  unix_listener auth-userdb {
>    mode = 0666
>  }
> }
> service imap-postlogin {
>  executable = script-login /usr/bin/postlogin-imap.sh
>  user = $default_internal_user
> }
> service imap {
>  drop_priv_before_exec = yes
>  executable = imap
>  process_limit = 10000
> }
> service pop3-postlogin {
>  executable = script-login /usr/bin/postlogin-pop.sh
>  user = $default_internal_user
> }
> }
> service pop3 {
>  drop_priv_before_exec = yes
>  executable = pop3
>  process_limit = 2500
> }
> ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
> ssl_key = </etc/pki/dovecot/private/dovecot.pem
> userdb {
>  driver = prefetch
> }
> userdb {
>  args = /etc/dovecot/conf.d/dovecot-sql.conf.ext
>  driver = sql
> }
> protocol lmtp {
>  mail_plugins = zlib
> }
> protocol lda {
>  mail_plugins = zlib
> }
> protocol imap {
>  mail_max_userip_connections = 100
>  mail_plugins = zlib
> }
> protocol pop3 {
>  mail_max_userip_connections = 30
>  mail_plugins = zlib
> }
> 
> 
> ...Jeff
>

On 2012-06-22 5:24 PM, Jeff Gustafson <ncjeffgus at zimage.com>
wrote:
> I'm getting an error backing up mailboxes. I'm using the mirror
> command:
>
> dsync -fvo mail_home=/home/users/bob mirror ssh vmail at 10.1.4.1 dsync -o
> mail_home=/home/.incoming_mail_migrations/users/bob
<snip>
> # 2.0.13: /etc/dovecot/dovecot.conf
As you are aware (since you participated in the thread discussion about 
this months ago), Timo is working on a total rewrite of dsync, and if 
memory serves, it is mainly for 2.1+, and it is not recommend to use it 
in earlier versions if you need reliability (ie, 2.0.x, as you are using)...

So, by all means, update and help timo make it better!

Timo? Care to elaborate on where you are with this, and how much of the 
rewrite is being applied to 2.1 (all of it?), or backported to earlier 
versions?

-- 

Best regards,

Charles