Plesk is probably the most needy of all the commercial panels, when it comes to installing it. Worst yet, the documentation at the Plesk site is something that I can only describe as a "word abortion". It's terrible.
So, for all you left scratching your heads (thanks Parallels 
), here's the "Cliff's Notes" for you! 
Now, I'm not a fan of Plesk for Linux, and often suggest against in forums online. (cPanel *is* better!) I'd used everything from version 6 to versino 11. ButS a Plesk-savvy user asked me to try out version 12, and see how it stacks up against older versions of Plesk -- as well as cPanel, DirectAdmin, ISPConfig and Virtualmin.
So he gave me a test license, a test VPS, and some quick notes to get started:
Code:
wget -O - http://autoinstall.plesk.com/plesk-installer | sh
But this was NOT it!
Code:
wget http://autoinstall.plesk.com/plesk-installer
chmod +x plesk-installer
./plesk-installer --all-versions
However, this works.
Code:
Welcome to the Parallels Installation and Upgrade Wizard!
===============================================================================
This wizard will guide you through the installation or upgrade process. Before
installing or upgrading Parallels products, be sure to back up your data.
To start the installation or upgrade, press N and then press Enter.
To quit the installer, press Q and then press Enter.
------ IMPORTANT ------
* Before installing or upgrading Parallels products, be sure to back up your data.
* New installation of product(s) should be performed on clean servers only.
Only the operating system with the networking option should be
installed for new installations.
Parallels will not be held liable for damages resulting from installation
of products on a server with anything other than a fresh installation of the
operating system for which the product installation was intended.
By using this Wizard you agree to the terms and conditions described at
http://www.parallels.com/en/company/terms/ and those of the Parallels Panel End User
License Agreement.
N) Next page; Q) Cancel installing
Select an action [N]:
Code:
Your host name must resolve to the correct IP address of your server, unless you are using network address translation (NAT).
Please quit Parallels Installer, fix the host name resolution problem,
and then try installing again.
You can skip the hostname check and continue the installation, however,
in such a case, the installer cannot guarantee successful installation.
Do you want to continue?
Type either Yes or No:
[N]:
Not Y
Not YES
Not yes
Oh no ... the mighty "Yes" only!
Code:
Select product software source
===============================================================================
You can install products by using any of the following sources:
* Local media
* Official Parallels server
* Other network site
Current settings:
Install products from Parallels server
Install required system packages from Parallels server
Store downloaded files in: /root/parallels
N) Next page; P) Go back; Q) Cancel installing
S) Change source; T) Change target directory;
Select an action and press ENTER [N]:
Code:
HTTP Proxy Setup
===============================================================================
If you are behind a firewall and use an HTTP proxy, you should specify the proxy server below.
If your proxy requires authentication, select "Use authentication"
and specify the username and password
Current settings:
Do not use proxy.
N) Next page; P) Go back; Q) Cancel installing;
S) Select proxy server; A) Use authentication;
Select the required action [N]:
Code:
File downloading products.inf3: 100% was finished.
File downloading plesk.inf3: 11%..20%..31%..40%..50%..60%..71%..82%..95%..100% was finished.
File downloading ppsmbe.inf3:
etc
... installs stuff.
Code:
Select the desired products and their versions
===============================================================================
The following product versions are available:
1. [ ] Parallels Plesk Panel
N) Go to the next page; P) Go to the previous page; Q) Cancel installing
To select a version, type the respective number;
Select an action [N]:
Enter 1 -- not N!
Code:
Select the desired products and their versions
===============================================================================
The following product versions are available:
1. [*] Parallels Plesk Panel
2. (*) Parallels Plesk Panel 12.0.18
3. ( ) Parallels Plesk Panel 12.0.17 (testing)
4. ( ) Parallels Plesk Panel 12.0.16 (testing)
5. ( ) Parallels Plesk Panel 12.0.15 (testing)
6. ( ) Parallels Plesk Panel 12.0.13 (testing)
7. ( ) Parallels Plesk Panel 12.0.12 (testing)
8. ( ) Parallels Plesk Panel 12.0.11 (testing)
9. ( ) Parallels Plesk Panel 12.0.10 (testing)
10. ( ) Parallels Plesk Panel 12.0.9 (testing)
11. ( ) Parallels Plesk Panel 12.0.7 (testing)
12. ( ) Parallels Plesk Panel 12.0.5 (testing)
13. ( ) Parallels Plesk Panel 11.6.4 (testing)
14. ( ) Parallels Plesk Panel 11.6.3 (testing)
15. ( ) Parallels Plesk Panel 11.6.2 (testing)
16. ( ) Parallels Plesk Panel 11.6.1 (testing)
17. ( ) Parallels Plesk Panel 11.5.30
18. ( ) Parallels Plesk Panel 11.0.9 (stable)
19. ( ) Parallels Plesk Panel 10.4.4 (stable)
20. ( ) Parallels Plesk Panel 10.3.1 (stable)
N) Go to the next page; P) Go to the previous page; Q) Cancel installing
To select a version, type the respective number;
Select an action [N]:
Code:
Would you like to help Parallels make better products by sending information
about installation, upgrade, and other problems? [Yes]:
Would you like to slow down your server by having it needlessly connect to Parallels all the time.
Code:
File downloading PSA_12.0.18/plesk-12.0.18-cos6-x86_64.inf3: 18%..20%..36%..43%..53%..61%..76%..97%..100% was finished.
File downloading PSA_12.0.18/plesk-patches-12.0.18-cos6-x86_64.inf3: 17%..28%..38%..54%..65%..74%..95%..100% was finished.
File downloading SITEBUILDER_12.0.5/sitebuilder-12.0.5-rhall-all.inf3:
etc
... installs stuff.
Code:
Select the installation type for Parallels Plesk Panel
===============================================================================
Installation types for the product:
1. (*) Typical
Install typically used components. Recommended for general use.
2. ( ) Without DNS server
Install typically used components without DNS server (BIND).
3. ( ) Full
Install all available components.
4. ( ) Custom
Custom components selection. Recommended only for experienced users.
N) Continue installation with selected type; P) Go the previous page; Q) Cancel installing;
L) View or change components marked for installation;
To select an installation type or choose another product, type the respective number;
Select an action [N]:
Code:
Determining the amount of free disk space
===============================================================================
Following amount of diskpace required in directories:
/usr/local: 1200.00 Mb.
Total required: 1200.00 Mb, available 17116.00 Mb.
N) Next page; P) Go back; Q) Cancel installing
Select an action [N]:
Code:
Preparing Your System for Product Installation
===============================================================================
There are 74 packages required for the product to function properly, which
were not found in your system.
There are 1 packages that need to be upgraded
in order to install the product.
N) Install packages;
S) Show a list of packages; L) Return to primary components list;
Q) Cancel installing;
Select an action [N]:
... installs LOTS of stuff.
Feel free to get up, grab a drink, use the bathroom. It'll be a while...
Code:
**** Product post-install started.
===> Checking for previous installation ... not found.
Trying to start service mysqld... mysqld (pid 31817) is running...
done
Trying to establish test connection... connected
done
Trying to create reverse DNS zone... /usr/local/psa/admin/sbin/mk_reverse_zone[6821]: Unable to resolve fqdn: Name or service not known
/usr/local/psa/admin/sbin/mk_reverse_zone[6821]: It is impossible to detect the FQDN of the host.
Please make sure that the host name is correctly specified in /etc/hosts and goes right after the host's IP address.
Depending on your OS, you might need to set the host name in /etc/HOSTNAME or /etc/hostname.
terminate called after throwing an instance of 'std::runtime_error'
what(): Error on configure reverse DNS zone for localhost : fail to detect hostname
WARNING!
Some problems are found during create reverse DNS zone - there is error during utility '/usr/local/psa/admin/sbin/mk_reverse_zone' execution, please fix the problem and run it again.(see log file: /var/log/plesk/install/plesk_12.0.18_installation.log)
Continue...
Code:
hostname: Unknown host
===> Cumulative APS controller upgrade (final stage) has been started.
===> Cumulative upgrade of APS controller (final stage) has been completed.
Starting psa... Starting sw-engine-fpm: [ OK ]
done
Starting xinetd service... done
Starting sw-cp-server service... done
Starting mysqld service... done
Starting named service... done
Starting postgresql service... not installed
Starting spamassassin service... not installed
Plesk: Starting Mail Server... already started
Starting psa... Starting sw-engine-fpm:
done
Starting drwebd service...
etc
... installs lots of stuff again.
Code:
Patches were installed successfully.
The changes were applied successfully.
[root~]#
Woo-hoo! Done.
Granted, that was easier than the free panels -- but at least those have ample documentation, that makes sense, and is found on the official site. Other commercial panels are literally one-line installers -- also with ample documentation that makes clear sense (not that you often need it). Why I had to guess and hunt with Plesk is really beyond me.
FYI: The Windows Plesk install is much easier.
