Aki Tuomi <aki.tuomi@dovecot.fi> writes:
On 24 February 2018 at 12:45 Neil Jerram < neil@ossau.homelinux.net> wrote:
Please could you help me to understand and fix why my dovecot IMAP performance is so bad? I've read through a lot of the performance-related material on the website, but I don't think that any of it could account for slowness at the level that I am seeing.
The simplest scenario is moving a message from my Inbox to another IMAP folder. Using Gnus as the client, the whole UI freezes for about 2 minutes (which I assume is until the move is complete), and journalctl on the dovecot server says:
Feb 24 10:24:24 arudy dovecot[1712]: imap(neil): Warning: Transaction log file /home/neil/dovecot-mail/.imap/INBOX/dovecot.index.log was locked for 98 seconds (Mailbox was synchronized)
or the same message with (rotating while syncing).
There must be something badly wrong in my setup, or perhaps in the spec of the server that dovecot is running on. What should I look at to start understanding this better?
Many thanks - Neil
Can you tell a bit more about your environment? Sounds like io issue
Thanks for your reply. I'm not sure exactly what you have in mind, but here are some starting points:
arudy:~# uname -a Linux arudy 4.13.0-1-686-pae #1 SMP Debian 4.13.4-2 (2017-10-15) i686 GNU/Linux
arudy:~# dovecot -n # 2.2.32 (dfbe293d4): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.20 (7cd71ba) # OS: Linux 4.13.0-1-686-pae i686 Debian buster/sid auth_mechanisms = plain login auth_username_format = %Ln auth_verbose = yes login_trusted_networks = 192.168.11.8 mail_access_groups = mail mail_fsync = never mail_location = mbox:~/dovecot-mail:INBOX=/var/mail/%u namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } plugin { antispam_backend = dspam antispam_dspam_args = --deliver;--user;%u antispam_dspam_binary = /usr/bin/dspam antispam_signature = X-DSPAM-Signature antispam_signature_missing = error antispam_spam = Spam antispam_trash = trash;Trash;Deleted Items; Deleted Messages fts = solr fts_solr = url=http://localhost:8080/solr/ sieve = file:~/sieve;active=~/.dovecot.sieve } postmaster_address = postmaster@ossau.homelinux.net protocols = " imap lmtp" service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0666 user = postfix } } service lmtp { unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0600 user = postfix } } ssl_cert = </etc/dovecot/cert.pem ssl_key = # hidden, use -P to show it userdb { driver = passwd } protocol lmtp { mail_fsync = optimized } protocol lda { mail_fsync = optimized }
arudy:~# cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 8 model name : Pentium III (Coppermine) stepping : 6 microcode : 0x8 cpu MHz : 935.497 cache size : 256 KB physical id : 0 siblings : 1 core id : 0 cpu cores : 1 apicid : 0 initial apicid : 0 fdiv_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pse36 mmx fxsr sse cpuid bugs : bogomips : 1870.99 clflush size : 32 cache_alignment : 32 address sizes : 36 bits physical, 32 bits virtual power management:
arudy:~# free total used free shared buff/cache available Mem: 248808 31572 4080 2576 213156 205880 Swap: 763052 20480 742572