set dovecot vsz_limit to 1/3 of available memory (#1096)

The `default_vsz_limit` is the maximum amount of virtual memory that can be allocated. It should be set *reasonably high* to avoid allocation issues with larger mailboxes. We're setting it to 1/3 of the total available memory (physical mem + swap) to be sure.

See here for discussion:
- https://www.dovecot.org/list/dovecot/2012-August/137569.html
- https://www.dovecot.org/list/dovecot/2011-December/132455.html
This commit is contained in:
Jan Schulz-Hofen 2017-03-01 19:59:48 +07:00 committed by Joshua Tauberer
parent d4baac2363
commit 3830facf78
1 changed files with 8 additions and 0 deletions

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@ -37,8 +37,16 @@ apt_install \
# of active IMAP connections (at, say, 5 open connections per user that
# would be 20 users). Set it to 250 times the number of cores this
# machine has, so on a two-core machine that's 500 processes/100 users).
# The `default_vsz_limit` is the maximum amount of virtual memory that
# can be allocated. It should be set *reasonably high* to avoid allocation
# issues with larger mailboxes. We're setting it to 1/3 of the total
# available memory (physical mem + swap) to be sure.
# See here for discussion:
# - https://www.dovecot.org/list/dovecot/2012-August/137569.html
# - https://www.dovecot.org/list/dovecot/2011-December/132455.html
tools/editconf.py /etc/dovecot/conf.d/10-master.conf \
default_process_limit=$(echo "`nproc` * 250" | bc) \
default_vsz_limit=$(echo "`free -tom | tail -1 | awk '{print $2}'` / 3" | bc)M \
log_path=/var/log/mail.log
# The inotify `max_user_instances` default is 128, which constrains