I would like to know how to start up k=10 Apache2 server processes upon Ubuntu 16.04 alpha release reboot. Yesterday, I read this URL, [https://rudd-o.com/linux-and-free-software/tuning-an-apache-server-in-5-minutes], which says to use Apache2 with the prefork.c module and set StartServers equal to 10<IfModule prefork.c>StartServers       4MinSpareServers    3MaxSpareServers   10ServerLimit      256MaxClients       256MaxRequestsPerChild  10000</IfModule>Unfortunately , my apache2 only has the event.c module. I tried upgrading apache2 to the prefork.c module with sudo apt-get install apache-mtm-prefork and the install error said no such package available because it may be outdated or obsolete. Then I tried sudo apt-get update and I received the same error message.My next step was to try to configure  the apache2 event module with StartServers = 5 by changing /etc/httpd.conf and then restarting my systemd apache.service file and my ps -ef | grep -in apache2 shows only 2 www-data apache2 processes and ps-ef | grep -in mod shows no mod-mono-server4 process.Furthermore, upon running apache2 at the bash shell command prompt it said syntax error APACHE2_LOCK_FILE environment variable missing. I discovered that APACHE2_LOCK_FILE is defined in my /etc/apache2/envvars file.The Ubuntu 16.04 apache2 man page says, In  general, apache2 should not be invoked directly, but rather should be invoked via /etc/init.d/apache2 or apache2ctl. The default Debian configuration requires environment variables that are defined in /etc/apache2/envvars  and  are  not  available  if  apache2  is  started  directly. However, apache2ctl can be used to pass arbitrary arguments to apache2.So I could use /etc/apache2/envars  , I edited my systemd apache.service file to use ExecStart = /etc/init.d/apache2 start and rebooted my Lenovo ThinkStation Ubuntu 16.04 desktop and to no avail, I still got only 2 www-data apache2 processes and ps-ef | grep -in mod shows no mod-mono-server4 process when I ran ps -ef | grep -in apache2.May I ask what I did  wrong and how to fix it? Please suggest tests I can do. I know that many Ubuntu 16.04 alpha release users will soon complain about the same problem  I experienced.
How to start up k=10 Apache2 server processes upon Ubuntu 16.04 alpha release reboot?
ubuntu;systemd;apache httpd;mono
First you can confirm that you already have the mpm_prefork module by seeing that's shipped in the apache2 package in 16.04. You'll see a couple results for it if you do this: dpkg -L apache2 | grep fork /etc/apache2/mods-available/mpm_prefork.conf /etc/apache2/mods-available/mpm_prefork.loadNow check which MPM module is enabled, and you'lll see that the Event MPM module is enabled while the Prefork module is not:  ls /etc/apache2/mods-enabled/mpm*It sounds like you want to disable the Event MPM module and enable the Prefork MPM module, which you can do with symlinks, and then restart Apache:sudo rm /etc/apache2/mods-enabled/mpm*sudo ln -s /etc/apache2/mods-available/*fork* /etc/apache2/mods-enabled/Perhaps then your StartServer directive will work as desired. The Event MPM server runs an event loop in a single process, so it doesn't all the extra processes.You also mentioned starting Apache and systemd. I recommend NOT starting Apache's http directly or with apache2ctl. ONLY control it through systemd for consistency. Here are some related systemd control commands, as examples:  sudo systemctl start   apache2 sudo systemctl stop    apache2 sudo systemctl restart apache2You had more questions in your comments about setting up Mono, ASPX and multiple apps. You should ask those questions separately and be clear whether you intend to serve multiple apps on a single domain, or multiple apps on multiple domains.To make the Apache2 service starts at boot, run:sudo systemctl enable apache2