You may be running up against Linux system/user limits. Run $ cat /proc/sys/kernel/pid_max and $ ulimit -a That should give some insight into your problem.
On 12/09/2015 2:53 PM, Rajesh M wrote:
hi
centos 6 64 bit
hex core processor with hyperthreading ie display shows 12 cores 16 gb ram 600 gb 15000 rpm drive
we are having around 4000 users on a server
i wish to allow 1500 pop3 and 1500 imap connections simultaneously.
need help regarding the settings to handle the above
imap-login, pop3-login imap pop3 service settings
i recently i got an error imap-login: Error: read(imap) failed: Remote closed connection (process_limit reached?)
my current dovecot config file
# 2.2.7: /etc/dovecot/dovecot.conf # OS: Linux 2.6.32-431.23.3.el6.x86_64 x86_64 CentOS release 6.5 (Final) auth_cache_negative_ttl = 0 auth_cache_ttl = 0 auth_mechanisms = plain login digest-md5 cram-md5 default_login_user = vpopmail disable_plaintext_auth = no first_valid_gid = 89 first_valid_uid = 89 log_path = /var/log/dovecot.log login_greeting = ready. mail_max_userip_connections = 50 mail_plugins = " quota" managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave namespace { inbox = yes location = prefix = separator = . type = private } passdb { args = cache_key=%u webmail=127.0.0.1 driver = vpopmail } plugin { quota = maildir:ignore=Trash quota_rule = ?:storage=0 } protocols = imap pop3 service imap-login { client_limit = 256 process_limit = 400 process_min_avail = 4 service_count = 0 vsz_limit = 512 M } service pop3-login { client_limit = 1000 process_limit = 400 process_min_avail = 12 service_count = 0 vsz_limit = 512 M } ssl_cert = </var/qmail/control/servercert.pem ssl_dh_parameters_length = 2048 ssl_key = </var/qmail/control/servercert.pem userdb { args = cache_key=%u quota_template=quota_rule=*:backend=%q driver = vpopmail } protocol imap { imap_client_workarounds = delay-newmail mail_plugins = " quota imap_quota" } protocol pop3 { pop3_client_workarounds = outlook-no-nuls oe-ns-eoh pop3_fast_size_lookups = yes pop3_lock_session = no pop3_no_flag_updates = yes }
thanks very much,
rajesh