To improve your documentation, I'll note the following comments:
URL: https://gluu.org/docs/ce/3.0.1/installation-guide/ (Preparing VM)
Redhat/Centos 7.3 needs to be referenced.
You should note that the gluu repo gets installed into /opt, and that /opt should be (a) not part the root filesystem, (b) a separate filesystem of size X. I used 10 GB, I don't know what you recommend.
The file descriptor write-up lacks information, like how to check what your settings for these items are before you start changing things. For instance, in RH 7.3 "cat /proc/sys/fs/file-max" gives 808424, far larger than 65535, so lowering the number is a bad idea.
Section on "Install Gluu Server", run setup.py, more info is needed on some of the items to be entered.
* hostname. Should this be a FQDN? Should this be the canonical name, or can it be a CNAME? What happens if you are upgrading and already have well-known hosts/cnames defined for your service? In my case I have a well known CNAME "idp.colby.edu" that points to my production shibb server, and the SSL certs use this name (even though the actual host name is something else).
* Maximum RAM. What is expected? Minimum needed? What percent of total RAM?
* Information on "Install oxAuth RP?" is missing
In general, more explanation about each of the install components would help.