HAProxy is the key element for the mail cluster. /etc/haproxy/haproxy.cfg global log /dev/log local0 log /dev/log local1 notice chroot /var/lib/hapro...
Data compression Prediction by Partial Matching (PPM) PPM is fast compression algorithm with a high compression ratio for text files (and pretty "average" for a...
ZPAQ http://mattmahoney.net/dc/zpaq.html http://mattmahoney.net/dc/10gb.png Great compression, but slow. The best feature is the possibility to add only the "diff...
Linux experiments Work in progress! Just some random notes on various experimental installations, configurations, setups, things to try... It might give you some ...
Installation/creation Container creation lxc create n container name t download d ubuntu r trusty a amd64 Creating a lightweight clone lxc clone s Creat...
GlusterFS http://www.gluster.org/ Gluster in containers https://www.flockport.com/build distributed storage nodes with lxc and gluster/ Create node in LXC mknod ...
Better and faster (de)compression than gzip... soon the new compression standard (but gzip will not dissappear in the next 100 years). Zstd can be used in the ker...
Brotli Aim is to replace gzip when it comes to HTTP(S) web compression. Major browsers already support it, but only over a TLS/SSL connection. The compression spe...
DNS "cluster" DNS is HA by design when using multiple servers. Use some free backup DNS servers, like * freedns.afraid.org * he.net Below a schematic overvi...
https://debian administration.org/article/718/DKIM signing_outgoing_mail_with_exim4 ... or in summary follow the steps below Generate the keys cd /etc/exim4 opens...
Google "reinvented" the good old gzip... Read more at https://github.com/google/zopfli. Backwards compatible with gzip/gunzip. Zopfli provides a better compressio...
Scalable (incoming) mail cluster This is one way to build a scalable mail infrastructure. Besides GlusterFS, the performance is pretty good. "Business Case" for t...
Previous setup (until August 2015) Old Toshiba laptop as server, using Debian Squeeze as host OS and vserver containers running Wheezy. digraph { rankdir=TB; ...
Blackhole routing Info at: https://www.spamhaus.org/drop/ Run this script from /etc/cron.daily on your routers/servers and it will reduce malicious traffic a lot....
/etc/ntp.conf # Some nearby ntp pool servers server nl.pool.ntp.org server be.pool.ntp.org server de.pool.ntp.org server uk.pool.ntp.org # My extra servers server...
WebDAV on Apache 2.4 Make sure the modules dav, davfs and auth_basic are enable. For Debian/Ubuntu distributions execute a2enmod dav a2enmod dav_fs a2enmod auth_b...
Kalob integrates (web)mail, calendar, todo, filesharing... In basis it is a combination of well known and solid opensource software, including Postfix, MySQL and...
more info https://help.ubuntu.com/community/FilesystemTroubleshooting Read only test (fast) fsck.ext4 f k c C0 /dev/sdaX Non destructive read/write test... sl...
more info at https://help.ubuntu.com/lts/serverguide/openldap server.html Server apt get install slapd ldap utils initial configuration dpkg reconfigure slapd C...