Dovecot / Postfix не может выделить память

У меня есть VPS с памятью 8 ГБ и работающий на Ubuntu 16.04.02 с Plesk Onyx.

С некоторых пор регулярно вылетает система на dovecot и / или postfix.

Версия Dovecot: 2.3.4.1-ubuntu16.04.19031416 Версия Postfix: 3.1.0-3ubuntu0.3

Я не могу найти, как это решить.

Этот сервер в основном используется для электронной почты (imap) и одного небольшого веб-сайта Wordpress с небольшим трафиком.

Иногда бывает достаточно перезапустить службу dovecot или postfix. Но иногда мне приходится перезапускать весь сервер

Ошибка в mail.log с самого начала сбоя.

> Jun 18 11:55:30 h2648771 dovecot: imap-login: Error: master(imap):
> net_connect_unix(imap) failed: Cannot allocate memory
> (client-pid=29864, client-id=1, rip=188.207.4.90, created 0 msecs ago,
> received 0/4 bytes) Jun 18 11:55:30 h2648771 dovecot: imap-login:
> Error: master(imap): net_connect_unix(imap) failed: Cannot allocate
> memory (client-pid=29866, client-id=1, rip=188.207.4.90, created 0
> msecs ago, received 0/4 bytes) Jun 18 11:55:30 h2648771 dovecot:
> imap-login: Error: socketpair() failed: Cannot allocate memory:
> user=<info@springstof.eu>, method=PLAIN, rip=188.207.4.90,
> lip=85.214.19.175, TLS, session=<H9L2HJaLeX28zwRa> Jun 18 11:55:30
> h2648771 dovecot: imap-login: Error: net_connect_unix(anvil) failed:
> Cannot allocate memory Jun 18 11:55:30 h2648771 dovecot: master:
> Error: service(imap-login): command startup failed, throttling for 2
> secs Jun 18 11:55:30 h2648771 dovecot: imap: Error:
> net_connect_unix(/var/run/dovecot/stats-writer) failed: Cannot
> allocate memory Jun 18 11:55:30 h2648771 dovecot: imap: Error:
> net_connect_unix(/run/dovecot/auth-master) failed: Cannot allocate
> memory

и т.д. / dovecot / dovecot.conf:

## Dovecot configuration file

# PLEASE DON'T EDIT ANYTHING IN THIS FILE! ANY CHANGES WILL BE LOST ON UPGRADE.
# Instead add your custom configuration to /etc/dovecot/conf.d/
# See the end of this file for details on customization.

# See example configuration files in /usr/share/doc/dovecot/example-config/
# See stock configuration files in /usr/share/doc/plesk-dovecot/dist-config/


# Space separated list of wanted authentication mechanisms.
# NOTE: See also disable_plaintext_auth setting.
auth_mechanisms = plain login digest-md5 cram-md5 apop

# Valid UID range should include popuser.
first_valid_uid = 30

# List of allowed characters in username. "'&" is added here to the default list.
auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890&.-_@'

# Plesk Maildirs layout.
mail_home = /var/qmail/mailnames/%Ld/%Ln
mail_location = maildir:/var/qmail/mailnames/%Ld/%Ln/Maildir

# Enable Maildir++ quota support.
mail_plugins = $mail_plugins quota

plugin {
  # Take quota limits from maildirsize file. If it doesn't exist, don't enforce.
  quota = maildir:User quota
  # LDA/LMTP allows saving the last mail to bring user from under quota to
  # over quota, if the quota doesn't grow too high. Default is to allow as
  # long as quota will stay under 10% above the limit. Also allowed e.g. 10M.
  # 0 doesn't allow going over quota (compatibility with Courier-IMAP behavior).
  quota_grace = 0
}


service auth {
  # Allow userdb lookups for popuser.
  unix_listener auth-userdb {
    mode = 0600
    user = popuser
    group = popuser
  }
}


# PEM encoded X.509 SSL/TLS certificate and private key.
ssl_cert = </etc/dovecot/private/ssl-cert-and-key.pem
ssl_key =  </etc/dovecot/private/ssl-cert-and-key.pem


# Protocols support.

protocols = imap pop3

protocol imap {
  mail_plugins = $mail_plugins imap_quota
}

protocol pop3 {
  # POP3 UIDL format similar to the one used by Courier-IMAP.
  pop3_uidl_format = UID%u-%v
}

# Applicable workarounds for various client bugs.
imap_client_workarounds = delay-newmail
pop3_client_workarounds = outlook-no-nuls oe-ns-eoh


# Default private namespace setup compatible with Courier-IMAP.

namespace inbox {
  separator = .
  prefix = INBOX.
  inbox = yes
}


# Logging verbosity and debugging.

# Log unsuccessful authentication attempts and the reasons why they failed.
#auth_verbose = yes

# In case of password mismatches, log the attempted password. Valid values are
# no, plain and sha1. sha1 can be useful for detecting brute force password
# attempts vs. user simply trying the same password over and over again.
#auth_verbose_passwords = no

# Even more verbose logging for debugging purposes.
#auth_debug = yes

# In case of password mismatches, log the passwords and used scheme so the
# problem can be debugged. Enabling this also enables auth_debug.
#auth_debug_passwords = yes

# Enable mail process debugging. This can help you figure out why Dovecot
# isn't finding your mails.
#mail_debug = yes

# Show protocol level SSL errors.
#verbose_ssl = yes


# Log format compatible with Plesk statistics collector.
mail_log_prefix = "service=%s, user=%u, ip=[%r]. "
pop3_logout_format = "rcvd=%i, sent=%o, top=%t/%p, retr=%r/%b, del=%d/%m, size=%s"
imap_logout_format = "rcvd=%i, sent=%o"

# Customizable part of configuration gets included below. The filenames are
# first sorted by their ASCII value and parsed in that order. The 00-prefixes
# in filenames are intended to make it easier to understand the ordering.
#
# Prefixes 10 through 20 and 90 through 95 (inclusive) are reserved for Plesk. 
# Please do not occupy them or edit files with these prefixes!
!include conf.d/*.conf

# vim:ts=2 sts=2 sw=2 et:

и т.д. / postfix / main.cf:

# See /usr/share/postfix/main.cf.dist for a commented, more complete version


# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# TLS parameters
smtpd_tls_cert_file = /etc/postfix/postfix.pem
smtpd_tls_key_file = $smtpd_tls_cert_file
smtpd_use_tls = yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = h1234567.stratoserver.net
alias_maps = hash:/etc/aliases, hash:/var/spool/postfix/plesk/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost.stratoserver.net, localhost, localhost.localdomain
mynetworks = 
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
recipient_delimiter = +
inet_protocols = all
virtual_mailbox_domains = $virtual_mailbox_maps, hash:/var/spool/postfix/plesk/virtual_domains
virtual_alias_maps = $virtual_maps, hash:/var/spool/postfix/plesk/virtual
virtual_mailbox_maps = , hash:/var/spool/postfix/plesk/vmailbox
transport_maps = , hash:/var/spool/postfix/plesk/transport
smtpd_tls_security_level = may
smtp_tls_security_level = may
smtp_use_tls = no
smtpd_timeout = 3600s
smtpd_proxy_timeout = 3600s
disable_vrfy_command = yes
smtpd_sender_restrictions = check_sender_access hash:/var/spool/postfix/plesk/blacklists, permit_sasl_authenticated
smtpd_client_restrictions = permit_mynetworks, permit_sasl_authenticated
smtp_send_xforward_command = yes
smtpd_authorized_xforward_hosts = 127.0.0.0/8 [::1]/128
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
virtual_mailbox_base = /var/qmail/mailnames
virtual_uid_maps = static:30
virtual_gid_maps = static:31
smtpd_milters = , inet:127.0.0.1:12768
sender_dependent_default_transport_maps = hash:/var/spool/postfix/plesk/sdd_transport_maps
virtual_transport = plesk_virtual
plesk_virtual_destination_recipient_limit = 1
mailman_destination_recipient_limit = 1
message_size_limit = 1024000000
virtual_mailbox_limit = 0
recipient_canonical_maps = tcp:127.0.0.1:12346
recipient_canonical_classes = envelope_recipient,header_recipient
smtpd_tls_ciphers = medium
smtpd_tls_mandatory_ciphers = medium
tls_medium_cipherlist = HIGH:!aNULL:!MD5
smtpd_tls_mandatory_protocols = TLSv1 TLSv1.1 TLSv1.2
smtpd_tls_protocols = TLSv1 TLSv1.1 TLSv1.2
mynetworks_style = subnet
authorized_flush_users = 
authorized_mailq_users = 
inet_interfaces = all

Кто-нибудь знает, как это решить?

Вывод

cat / proc / user_beancounters

Version: 2.5
       uid  resource                     held              maxheld              barrier                limit              failcnt
  2648771:  kmemsize                 78343618            423485440  9223372036854775807  9223372036854775807                    0
            lockedpages                     0                   16              2097152              2097152                    0
            privvmpages               1138097              1401250  9223372036854775807  9223372036854775807                    0
            shmpages                    86247                86261  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numproc                       211                  330                  700                  700                    0
            physpages                 1052473              1520136              2097152              2097152                    0
            vmguarpages                     0                    0              2097152              2097152                    0
            oomguarpages               576172               606928              2097152              2097152                    0
            numtcpsock                     67                  214                  750                  750                    0
            numflock                      478                  489  9223372036854775807  9223372036854775807                    0
            numpty                          0                    0  9223372036854775807  9223372036854775807                    0
            numsiginfo                      0                   60  9223372036854775807  9223372036854775807                    0
            tcpsndbuf                 5779952              9023696  9223372036854775807  9223372036854775807                    0
            tcprcvbuf                 1097728              3635784  9223372036854775807  9223372036854775807                    0
            othersockbuf               871624              2229824  9223372036854775807  9223372036854775807                    0
            dgramrcvbuf                     0               296480  9223372036854775807  9223372036854775807                    0
            numothersock                  469                  916                  950                  950                    0
            dcachesize               41858232            380313547  9223372036854775807  9223372036854775807                    0
            numfile                      6049                 8635  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            dummy                           0                    0  9223372036854775807  9223372036854775807                    0
            numiptent                     363                  365  9223372036854775807  9223372036854775807                    0