How do I know if the open source version of Chef was installed correctly?

I am using RHEL 7.2. I want to install the free version of Chef.

After I installed it, I went to this file: /var/opt/opscode/local-mode-cache/chef-stacktrace.out

I saw this:

Chef::Exceptions::MultipleFailures: Chef::Exceptions::MultipleFailures
/opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/mixlib-shellout-2.2.6/lib/mixlib/shellout/unix.rb:316:in fork' /opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/mixlib-shellout-2.2.6/lib/mixlib/shellout/unix.rb:316:in fork_subprocess'
/opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/mixlib-shellout-2.2.6/lib/mixlib/shellout/unix.rb:93:in `run_command'

...

/opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/chef-12.12.19/lib/chef/application.rb:227:in run_chef_client' /opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/chef-12.12.19/lib/chef/application/client.rb:419:in run_application'
/opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/chef-12.12.19/lib/chef/application.rb:59:in run' /opt/opscode/embedded/lib/ruby/gems/2.1.0/gems/chef-12.12.19/bin/chef-client:26:in <top (required)>'
/opt/opscode/embedded/bin/chef-client:23:in load' /opt/opscode/embedded/bin/chef-client:23:in '

I think I may not have enough memory. I want to know if Chef is installed despite what I found above.

The command chef-server-ctl status looked good.

But I do not know how to run this command and it does not work for me
as there are MANY version.rb files. I cannot find the location it's referring to:

cat /usr/lib/ruby/vendor_ruby/chef-server/version.rb

The above command is supposed to tell you what version of Chef you have installed.

I tried to run this command:

chef-server-ctl user-create ec2-user John Doe jdoe@acme.com 'P@$$W0rd!' --filename /home/ec2-user/goodfile

I got this error:

ERROR: CONFIGURATION ERROR:Specified config file /etc/opscode/pivotal.rb does not exist

The pivotal.rb file was indeed missing from /etc/opscode/. Once Chef is installed properly, a different team will take over. I want to know If I did it correctly. What should I do?

I am also thinking you may not have enough memory. I have not had this issue myself with only running on 2GB of RAM. I saw this same issue online.

How much RAM is on this host? They fixed their issues by increasing RAM from 512MB to 1512MB.
Then running:
chef-server-ctl reconfigure

I hope that helps.