How can I remove the GUI bits from a Red Hat Enterprise Linux install?

Question

I am looking at a farm of RedHat Enterprise Linux (RHEL) 5.3 servers, which all have GNOME and Xorg installed, none of which need them. They were deployed by a 3rd party from a VM template, and I don't know all of their history. What I do know is none of them run an application that actually requires having a full GUI installed. However, it is possible, that some run an application that requires some X libraries (ImageMagick comes to mind).

According to yum grouplist, the 'X Window System' group is not installed, so I can't use yum groupremove here.

Is there a sufficiently low-in-the-dependency-chain package, or packages, that I can remove, which will pull out Gtk, GNOME and Xorg? Alternatively, if it generates a list of packages to remove before starting, we can reinstall the applications we need, which will pull back the X libraries, when we are done.

Solution 1

I haven't done this with real, live RHEL, but I have pried X out of CentOS 5.1 and 5.2. (I've been pulling X off of Redhat-derived distros for years... ever since the dependencies were made such that you, basically, had to install X, whether you wanted it or not.)

I don't recall the exact dependencies, but, as I recall, there are some annyoing dependencies that require a "--nodeps" argument to RPM in order to get the offending RPMs to remove. I just start ripping out packages I don't need, adding more and more packages to the "rpm -e" command-line, and finally adding "--nodeps" when necessary.

I don't know that I'd recommend doing this for production machines. I don't deploy any quantity of CentOS in production environments, so it's probably alright that I potentially screw up my installation. In a production environment, disk space is cheap. I don't like having unnecessary software installed, from a security perspective, but The Right Thing^(tm) is probably to rebuild the packages with offending dependencies (without the offending dependencies, obviously) rather than just ripping out and potentially making a system unusable.

Solution 2

You might also consider just not starting the X server / GDM at boot and leaving the packages there. I guess they will take up some space and add time to updates, but other than that I wouldn't think they will cause any issues.

For your situation you might really want them removed, or you might have already considered this, but I just though I would put it out there :-)

Comments

[crb]

I agree with your "the right thing" assessment, but at this point, I'd like to investigate a smarter answer, at least for our dev/staging environments. If you were able to remember any dependency problems you had it would be great.

[Spence]

I'm not sure what you mean by "a smarter answer". Anything other than rebuilding packages w/o dependencies is going to leave you with broken dependencies as far as RPM is concerned. You'll need to test all your applications to insure that they function w/ the broken dependencies, since anything you install is going to assume the dependent packages are there. If it'll help, I can send you the output of an "rpm -qa" from one of my CentOS 5.2 boxes. I didn't really keep notes of what I've removed, since I don't deploy CentOS in production to my Customers.

[crb]

Sorry for not being clear; I meant "smarter" solely in terms of not taking as long to rebuild entire machines and remigrate. Ultimately, I want to be able to say "if I remove package A, packages W X Y and Z" will be removed, and if I know I don't need W-Z, I can go ahead and remove A safely. I suspect that using yum here would be safer than plain rpm.

[crb]

Thanks Kyle, that's where we are at, at the moment; I hoped that this lovely dependency-resolving system Red Hat has would make doing the tidy up trivial.