after replication with compression quotas are wrong

[Arnaud Abélard]

Hello,

We are very long time happy dovecot users (since 2008 at least). We have 
around 90k mailboxes and since we had to move away from our NAS storage 
to a ceph storage I jumped on the opportunity to enable compression with 
the zlib plugin and dovecot's replication mecanism. We are using 
debian's dovecot 2.2.27 packages on production and our new server is 
running dovecot's own ce-2.3.17 packages.

On the production server everything works fine but on the new server, 
replicated mailboxes' quota is all wrong:

on production:
# doveadm quota get -u dummy-c-1
Quota name        Type     Value  Limit                             %
Quota Utilisateur STORAGE 660026 976563                            67
Quota Utilisateur MESSAGE   8651      -                             0

on new server:
doveadm quota get -u dummy-c-1
Quota name        Type      Value  Limit                           %
Quota Utilisateur STORAGE 1125251 976563                         115
Quota Utilisateur MESSAGE   16646      -                           0

If I add all the S flag from the filenames n both servers I get exactly 
the same usage, which is coherent with the quota on the production server:

# find . -type f | grep 'S=' | awk -F'S=' '{print $2}' | awk -F',' 
'{print $1}' | awk -F':' '{print $1}' | paste -sd+ | bc -l
675865938

And I have exactly the same amountof mails on the two server, the 
replication works as expected, no unwanted duplication of mails occurs.

Of course, I've tried to ask dovecot to recalculate quotas with doveadm 
quota recalc -u <username>, but it doesn't fix the problem.

What am I missing?

Thanks,

Arnaud

PS: Here is my doveconf -n output:

# 2.3.17 (e2aa53df5b): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.17 (054dddfa)
# OS: Linux 4.19.0-18-amd64 x86_64 Debian 10.11
# Hostname: gromel-test
auth_cache_size = 10 k
auth_verbose = yes
disable_plaintext_auth = no
doveadm_password = # hidden, use -P to show it
hostname = gromel1.univ-nantes.prive
lda_mailbox_autosubscribe = yes
listen = *
log_timestamp = "%Y-%m-%d %H:%M:%S "
login_trusted_networks = (...)
mail_gid = 5000
mail_location = maildir:%h
mail_plugins = quota zlib notify replication
mail_privileged_group = vmail
mail_uid = 5000
maildir_stat_dirs = yes
maildir_very_dirty_syncs = yes
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character subaddress comparator-i;ascii-numeric relational regex 
imap4flags copy include variables body enotify environment mailbox date 
index ihave duplicate mime foreverypart extracttext
namespace {
   inbox = yes
   location =
   prefix = INBOX.
   separator = .
   type = private
}
passdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
plugin {
   quota = maildir:Quota Utilisateur
   quota_exceeded_message = Cet utilisateur a dépassé son quota, votre 
message n'a pu lui être livré.
   quota_full_tempfail = yes
   quota_rule = *:storage=1000M
   quota_rule2 = INBOX.Trash:storage=+100M
   sieve = ~/dovecot.sieve
   sieve_dir = ~/sieve
   sieve_extensions = -vacation
   sieve_global_dir = /var/lib/dovecot/sieve/global/
   sieve_max_redirects = 1
   zlib_save = gz
   zlib_save_level = 6
}
postmaster_address = postmaster@<snip>
protocols = imap pop3 sieve
replication_max_conns = 50
service auth {
   client_limit = 49452
   unix_listener auth-userdb {
     group = vmail
     mode = 0600
     user = vmail
   }
   user = root
}
service dict {
   unix_listener dict {
     mode = 0600
     user = vmail
   }
}
service doveadm {
   inet_listener {
     port = 12345
   }
}
service imap-login {
   process_min_avail = 8
   service_count = 0
   user = mail
}
service imap {
   executable = imap
   process_limit = 16384
   vsz_limit = 2 G
}
service managesieve-login {
   inet_listener sieve {
     port = 4190
   }
   process_min_avail = 8
   service_count = 0
   user = mail
   vsz_limit = 2 G
}
service managesieve {
   drop_priv_before_exec = yes
   process_limit = 16384
}
service pop3-login {
   process_min_avail = 8
   service_count = 0
   user = mail
}
service pop3 {
   drop_priv_before_exec = yes
   process_limit = 16384
}
ssl = no
userdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
verbose_proctitle = yes
protocol imap {
   mail_max_userip_connections = 50
   mail_plugins = quota zlib notify replication imap_quota zlib
}
protocol pop3 {
   mail_plugins = quota zlib notify replication
}
protocol sieve {
   mail_max_userip_connections = 10
}
protocol lda {
   mail_plugins = quota zlib notify replication sieve zlib
}




-- 
Arnaud Abélard
Responsable pôle Système et Stockage
Service Infrastructures
DSIN Université de Nantes
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