Installing Drupal

I've entered the trusted host patterns code in settings.php:

I'm trying to get the coupon module working on drupal 7. Once I set up my discount and once a user adds items to the cart every page gives and error check log.

2015/11/05 23:58:00 [error] 16513#0: *720 FastCGI sent in stderr: "PHP message: PHP Fatal error: Call to undefined function commerce_coupon_type_enable() in /var/www/html/drupal/sites/all/modules/commerce_coupon_pct/commerce_coupon_pct.install on line 57"

So far the only way to fix the error on every page is to disable all coupon and discount modules.

Drupal: 8.0.0-RC2
O/S: Centos 6.7
PHP: 5.6.14
MySQL: 5.5.46

I'm installing Drupal 8 on my Centos 6 server. To do this I needed to upgrade both PHP and MySQL. However, I'm now getting the following error message from the installer:

The libmysqlclient driver version 5.1.54 is less than the minimum required version. Upgrade to libmysqlclient version 5.5.3 or up, or alternatively switch mysql drivers to MySQLnd version 5.0.9 or up.

I'm trying to install Drupal 8 on Ubuntu with Nginx, HHVM and PostgreSQL. Relevant versions:

Drupal: 8.0.0-rc2
Ubuntu: 14.04 LTS
Nginx: 1.4.6
HHVM: 3.10.1
PostgreSQL: 9.3.10

The issue is that when I run the Drupal 8 install script, I get as far as configuring the database, then when I click save and continue, HHVM crashes and I get a "502 Bad Gateway" error in the browser.

The install steps I'm taking are:

Hi!

When installing Druapl 8 RC2 i get this error message at Requirements review:

Warning: Zend OPcache API is restricted by "restrict_api" configuration directive in system_requirements() (line 244 of core/modules/system/system.install).

system_requirements('install')
drupal_check_profile('standard', Array)
install_check_requirements(Array)
install_verify_requirements(Array)
install_run_task(Array, Array)
install_run_tasks(Array)
install_drupal(Object)

further:

I have some freelance work in the pipeline and I was thinking about using Linode to host a Drupal installation, has anyone had any experience with that? Good or bad? Linda seems to have a lot of good documentation about how to get a Drupal installation working, and since their service is just basically renting out a VPS, I can't see any major incompatibility problems. But any feedback or anecdotal evidence would be appreciated.