<div dir="ltr"><div>Hi,</div><div><br></div><div>I have 2 dovecot servers, server1.domain.tld and server2.domain.tld 
and I'm not able to do a simple doveadm backup command between them.

</div><div>Dovecot version 2.3.11.3, on debian buster, (installed from apt) <br></div><div><br></div><div>I try to execute this cmd between to of my dovecot servers :</div><div><br></div><div>doveadm sync -u postmaster@domain.tld remote:root@server2.domain.tld</div><div><br></div><div>and it returns : <br></div><div><br></div><div>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: userdb lookup(postmaster@domain.tld): Started userdb lookup<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: conn unix:/var/run/dovecot/auth-userdb: Connecting<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: conn unix:/var/run/dovecot/auth-userdb (pid=118292,uid=0): Client connected (fd=15)<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: userdb lookup(postmaster@domain.tld): auth USER input: postmaster@domain.tld mail=maildir:/mails/2/domain.tld/postmaster/Maildir:INDEX=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld home=/mails/2/domain.tld/postmaster quota_rule=*:storage=3145728000b:messages=500k<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: userdb lookup(postmaster@domain.tld): Finished userdb lookup (username=postmaster@domain.tld mail=maildir:/mails/2/domain.tld/postmaster/Maildir:INDEX=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld home=/mails/2/domain.tld/postmaster quota_rule=*:storage=3145728000b:messages=500k)<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Added userdb setting: mail=maildir:/mails/2/domain.tld/postmaster/Maildir:INDEX=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Added userdb setting: plugin/quota_rule=*:storage=3145728000b:messages=500k<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Effective uid=65534, gid=65534, home=/mails/2/domain.tld/postmaster<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Quota root: name=Mailbox backend=count args=<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Quota rule: root=Mailbox mailbox=* bytes=3145728000 messages=512000<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Quota grace: root=Mailbox bytes=314572800 (10%)<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Namespace inbox: type=private, prefix=INBOX., sep=., inbox=yes, hidden=no, list=yes, subscriptions=yes location=maildir:/mails/2/domain.tld/postmaster/Maildir:INDEX=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): maildir++: root=/mails/2/domain.tld/postmaster/Maildir, index=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld, indexpvt=, control=, inbox=/mails/2/domain.tld/postmaster/Maildir, alt=<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Namespace : type=private, prefix=, sep=, inbox=no, hidden=yes, list=no, subscriptions=no location=fail::LAYOUT=none<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): none: root=, index=, indexpvt=, control=, inbox=, alt=<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): quota: quota_over_flag check: quota_over_script unset - skipping<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): brain M: Namespace INBOX. has location maildir:/mails/2/domain.tld/postmaster/Maildir:INDEX=/var/lib/dovecot/indexes/domain.tld/postmaster@domain.tld<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): Namespace INBOX.: Using permissions from /mails/2/domain.tld/postmaster/Maildir: mode=0700 gid=default<br>doveadm(postmaster@domain.tld): Error: remote(/var/run/dovecot/doveadm-server): read(root@server2.domain.tld) failed: EOF (version not received)<br>doveadm(postmaster@domain.tld): Debug: remote(/var/run/dovecot/doveadm-server): auth-master: conn unix:/var/run/dovecot/auth-userdb (pid=118292,uid=0): Disconnected: Connection closed (fd=15)</div><div></div><div><br></div><div>On the destination server, 
 I can see that the destination server is well retrieving the user's info in userdb, before saying : 

</div><div>server2 dovecot: doveadm: Error: read(<local>) failed: EOF (version not received)</div><div><br></div><div>I tried to activate verbosity everywhere, but It does not show anything, like :</div><div><br></div><div>ssh -v -lroot server2.domain.tld doveadm dsync-server -upostmaster@domain.tld -U</div><div><br></div><div>debug1: Authentication succeeded (publickey).<br>Authenticated to server2;domain.tld ([w.x.y.z]:22).<br>debug1: channel 0: new [client-session]<br>debug1: Requesting <a href="mailto:no-more-sessions@openssh.com">no-more-sessions@openssh.com</a><br>debug1: Entering interactive session.<br>debug1: pledge: network<br>debug1: client_input_global_request: rtype <a href="mailto:hostkeys-00@openssh.com">hostkeys-00@openssh.com</a> want_reply 0<br>debug1: Remote: /root/.ssh/authorized_keys:4: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding<br>debug1: Remote: /root/.ssh/authorized_keys:4: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding<br>debug1: Sending environment.<br>debug1: Sending env LANG = fr_FR.UTF-8<br>debug1: Sending command: doveadm dsync-server -upostmaster@domain.tld -U<br>debug1: client_input_channel_req: channel 0 rtype exit-status reply 0<br>debug1: client_input_channel_req: channel 0 rtype <a href="mailto:eow@openssh.com">eow@openssh.com</a> reply 0<br>debug1: channel 0: free: client-session, nchannels 1<br>Transferred: sent 2800, received 2820 bytes, in 0.1 seconds<br>Bytes per second: sent 25466.2, received 25648.1<br>debug1: Exit status 0</div><div><br></div><div>If somebody can tell me some hints to go further, it'll be very apreciate.</div><div><br></div><div>Thanks !</div><div><br></div><div>Here is the doveconf -n output (the two servers have the same)</div><div><br></div><div># 2.3.11.3 (502c39af9): /etc/dovecot/dovecot.conf<br># Pigeonhole version 0.5.11 (6c69c917)<br># OS: Linux 4.19.0-12-amd64 x86_64 Debian 10.6<br># Hostname: server1<br>auth_cache_negative_ttl = 0<br>auth_cache_size = 100 M<br>auth_cache_ttl = 5 mins<br>auth_master_user_separator = *<br>default_client_limit = 2000<br>disable_plaintext_auth = no<br>doveadm_api_key = # hidden, use -P to show it<br>doveadm_worker_count = 50<br>listen = w.x.y.z<br>mail_fsync = always<br>mail_gid = nogroup<br>mail_location = maildir:~/Maildir:INDEX=/var/lib/dovecot/indexes/%d/%n<br>mail_max_userip_connections = 300<br>mail_plugins = quota<br>mail_uid = nobody<br>maildir_very_dirty_syncs = yes<br>namespace inbox {<br>  inbox = yes<br>  location =<br>  mailbox Drafts {<br>    auto = subscribe<br>    special_use = \Drafts<br>  }<br>  mailbox Junk {<br>    auto = subscribe<br>    autoexpunge = 90 days<br>    special_use = \Junk<br>  }<br>  mailbox Sent {<br>    auto = subscribe<br>    special_use = \Sent<br>  }<br>  mailbox "Sent Messages" {<br>    auto = no<br>    special_use = \Sent<br>  }<br>  mailbox Trash {<br>    auto = subscribe<br>    autoexpunge = 90 days<br>    special_use = \Trash<br>  }<br>  prefix = INBOX.<br>  separator = .<br>}<br>passdb {<br>  args = /etc/dovecot/master-users<br>  driver = passwd-file<br>  master = yes<br>  result_success = continue<br>}<br>passdb {<br>  args = /etc/dovecot/dovecot-sql.conf.ext<br>  driver = sql<br>}<br>plugin {<br>  imapsieve_mailbox1_before = file:/var/lib/dovecot/sieve/report-spam.sieve<br>  imapsieve_mailbox1_causes = COPY<br>  imapsieve_mailbox1_name = INBOX.Junk<br>  imapsieve_mailbox2_before = file:/var/lib/dovecot/sieve/report-ham.sieve<br>  imapsieve_mailbox2_causes = COPY<br>  imapsieve_mailbox2_from = INBOX.Junk<br>  imapsieve_mailbox2_name = *<br>  quota = count:Mailbox<br>  quota_rule = *:storage=1G:messages=500k<br>  quota_vsizes = yes<br>  sieve = file:~/sieve;active=~/.dovecot.sieve<br>  sieve_before = /var/lib/dovecot/sieve/antispam.sieve<br>  sieve_global_extensions = +vnd.dovecot.pipe +vnd.dovecot.environment +spamtest +spamtestplus<br>  sieve_pipe_bin_dir = /var/lib/dovecot/sieve<br>  sieve_plugins = sieve_imapsieve sieve_extprograms<br>  sieve_spamtest_max_header = X-Spam-Status: [[:alnum:]]+, score=-?[[:digit:]]+\.[[:digit:]] required=([[:digit:]]+\.[[:digit:]]).*<br>  sieve_spamtest_status_header = X-Spam-Status: [[:alnum:]]+, score=(-?[[:digit:]]+\.[[:digit:]])<br>  sieve_spamtest_status_type = score<br>}<br>pop3_fast_size_lookups = yes<br>pop3_reuse_xuidl = yes<br>pop3_save_uidl = yes<br>pop3_uidl_format = %f<br>protocols = imap pop3 lmtp<br>service anvil {<br>  client_limit = 5000<br>  unix_listener anvil-auth-penalty {<br>    mode = 00<br>  }<br>}<br>service auth {<br>  client_limit = 0<br>}<br>service doveadm {<br>  inet_listener http {<br>    port = 8080<br>  }<br>  vsz_limit = 2 G<br>}<br>service imap-login {<br>  process_limit = 2000<br>  service_count = 1<br>}<br>service imap {<br>  client_limit = 1<br>  process_limit = 5000<br>  vsz_limit = 1 G<br>}<br>service indexer-worker {<br>  process_limit = 20<br>}<br>service lmtp {<br>  client_limit = 1<br>  inet_listener lmtp {<br>    port = 24<br>  }<br>  process_limit = 200<br>  process_min_avail = 20<br>  vsz_limit = 1 G<br>}<br>service pop3-login {<br>  process_limit = 2000<br>  service_count = 1<br>}<br>ssl = no<br>submission_host = smtp.domain.tld:25<br>userdb {<br>  args = /etc/dovecot/dovecot-sql.conf.ext<br>  driver = sql<br>}<br>protocol lmtp {<br>  mail_plugins = quota sieve<br>}<br>protocol imap {<br>  mail_plugins = quota imap_sieve imap_quota<br>}</div><div><br></div><div><br></div></div>