I had installed virtualmin on a RHEL system and a couple of very strange problems have cropped up.
Firstly, the Apache test page now says - powered by CentOS instead of RHEL. All the files and filesystems are intact therefore I am at a loss as to why it would report another version of linux altogether.
Secondly, my sudo access has been overwritten / removed after installation. It just comes up with a message that XXXX (username) does not have sudo access....etc
And lastly, trying to access the virtualmin page over the port 10000 is just returning an "unable to connect" error. [Since I am locked out of using sudo, I am at a loss of how to proceed].
Thank you in advance for your help.
The Apache package we ship is a rebuild of the SRPM from CentOS. The default page is simply an HTML file...it is not "reporting" anything, really, except that you haven't setup any websites yet. On CentOS/RHEL Apache has to be rebuilt in order to support virtual servers in /home when using suexec. So, this is expected behavior and no reason for alarm. We used to ship a custom error page instead (with Virtualmin logo instead of CentOS, but the patch broke a while back and I never got around to fixing it...might go back to that next time we roll an Apache update).
Virtualmin did not touch your sudoers file. That problem is unrelated to the Virtualmin installation. (I wrote the install.sh and the virtualmin-base package; I'm 100% certain your sudoers issue is unrelated to Virtualmin). I don't have any guesses about what went wrong there, or how to fix it if you don't have any way to access the machine as root (rebooting into single user mode would be the right thing if you have hardware access or can get access via a KVM from your hosting provider/colo).
We would need to see the last few dozen lines of the install log to know what went wrong with the Virtualmin installation, and why Webmin failed to start.