Reword the 512 memmory advise.

doc/install/requirements.md

@@ -50,12 +50,12 @@ We love [JRuby](http://jruby.org/) and [Rubinius](http://rubini.us/) but GitLab
 
 ### Memory
 
-- 512MB is the absolute minimum but we do not recommend this amount of memory.
-You will need to configure minimum 1.5GB of swap space.
-With 1.5GB of swap space you must configure only one unicorn worker.
-With one unicorn worker only git over ssh access will work because the git over HTTP access requires two running workers (one worker to receive the user request and one worker for the authorization check).
-If you use SSD storage and configure 1.5GB of swap space you can use two Unicorn workers, this will allow HTTP access but it will still be slow.
-Consider installing GitLab on Ubuntu as installation on CentOS could be unsuccessful with this amount of memory.
+- 512MB is the absolute minimum but we strongly **advise against** this amount of memory.
+You will need to configure a minimum of 1.5GB of swap space to make the Omnibus package reconfigure run succeed.
+If you use a magnetic (non-SSD) swap drive we recommend to configure only one Unicorn worker.
+With one Unicorn worker only git over ssh access will work because the git over HTTP access requires two running workers (one worker to receive the user request and one worker for the authorization check).
+If you use a SSD drive you can use two Unicorn workers, this will allow HTTP access although it will be slow.
+Consider installing GitLab on Ubuntu instead of CentOS because sometimes CentOS gives errors during installation and usage with this amount of memory.
 - 1GB RAM + 1GB swap supports up to 100 users
 - **2GB RAM** is the **recommended** memory size and supports up to 500 users
 - 4GB RAM supports up to 2,000 users