Arch Linux - Unable to connect to ZM db.could not find drive

[eduardomezencio]

After installing in Arch Linux following the instructions in the arch wiki, I got some problems. The first is that I can't start it with 'systemctl start zoneminder' because it gives an error saying that it does not have permission to create the temporary folder /var/run/zm. I 'solve' this by creating it manually and then changing it's owner:group to http:http. After this, systemctl can start zoneminder alright.
With zoneminder running, when I access the page, the only thing that appears is "Unable to connect to ZM db.could not find driver". I could not find anything related to this problem anywhere.

EDIT: just to add a little information, I also saved some text that appeared after installing the package with pacman and followed it's instructions. It reads:

warning: directory permissions differ on /usr/share/polkit-1/rules.d/
filesystem: 700 package: 755
Note for mysql:
==> To run Zoneminder, you must install the database running mysql service (as root):
==> "rc.d start mysqld" (in initscripts) or "systemctl start mysqld.service" (in systemd)
==> and add Zoneminder database typing (with passsword):
==> "mysqladmin --defaults-file=/etc/mysql/my.cnf -p -f reload"
==> "cat /usr/share/zoneminder/db/zm_create.sql | mysql --defaults-file=/etc/mysql/my.cnf -p"
==> "echo 'grant lock tables, alter,select,insert,update,delete on zm.* to 'zmuser'@localhost identified by "zmpass";' | mysql --defaults-file=/etc/mysql/my.cnf -p mysql"
==> (or without passsword):
==> "mysqladmin --defaults-file=/etc/mysql/my.cnf -f reload"
==> "cat /usr/share/zoneminder/db/zm_create.sql | mysql --defaults-file=/etc/mysql/my.cnf"
==> "echo 'grant lock tables, alter,select,insert,update,delete on zm.* to 'zmuser'@localhost identified by "zmpass";' | mysql --defaults-file=/etc/mysql/my.cnf mysql"

Note for php:
==> You must uncomment that line in /etc/php/php.ini:
==> "extension=mysql.so"
==> check and make sure these are uncommented:
==> "extension=gd.so"
==> "extension=gettext.so"
==> "extension=mcrypt.so"
==> "extension=mysqli.so"
==> "extension=session.so"
==> "extension=sockets.so"
==> "extension=openssl.so"
==> "extension=ftp.so"
==> "extension=zip.so"
==> check and add to open_basedir "/etc" and
==> "/srv/http/zoneminder" like so
==> "open_basedir = /home:/tmp:/usr/share/pear:/etc:/srv/http/zoneminder"
==> and set your timezone in php.ini:
==> "date.timezone = <your_country>/<your_city>"

Note for apache:
==> You must edit /etc/httpd/conf/httpd.conf and add the line:
==> "LoadModule php5_module modules/libphp5.so"
==> and:
==> "Include /etc/httpd/conf/extra/php5_module.conf"
==> "Include /etc/httpd/conf/extra/httpd-zoneminder.conf"
Optional dependencies for zoneminder
netpbm [installed]

The only part I did nothing about is the polkit warning:

directory permissions differ on /usr/share/polkit-1/rules.d/ filesystem: 700 package: 755

, because I have no idea what this is.

[DiskCrasher]

I'm getting the "Unable to connect to ZM db.could not find driver" error on openSUSE. An update must be to blame because it had been working for a long time. Not sure where the problem lies or how to troubleshoot?