Friday, May 27, 2016

Postfix configuration


  1. Allow RELAYing for
  2. Allow such relaying ONLY for hosts in the local network



inet_interfaces = all

 mynetworks =  (local network IP)

smtpd_recipient_restrictions =
        check_recipient_access hash:/etc/postfix/recipient_access

/etc/postfix/recipient_access:   OK

sudo postmap /etc/postfix/recipient_access
sudo service postmap restart

Sunday, March 27, 2016

kswapd0 high cpu consumption

OS: Ubuntu 15.10
Linux Kernel: 4.2.0-25-generic

Running MongoDB gets the CPU consumption high, with the culprit being kswapd0 process


add this to /etc/rc.local:
echo madvise > /sys/kernel/mm/transparent_hugepage/enabled

As per this URL:

The next attempt:

echo 3 > /proc/sys/vm/drop_caches

One more attempt:

worked around by commenting out line 2 in /lib/udev/rules.d/40-vm-hotadd.rules.

And the last attempt really worked:

Just updated to the last kernel update on ubuntu 15.10 :-)