Re: dont hate me for this question
Indeed it has been discussed before.
Technically, there is no need to shutdown X to replace the files that need to be replaced during a driver update. In Linux, it is perfectly possible to replace a file that is open. In Windows there are issues with that, but they are not relevant to Linux.
What Nvidia (AaronP) claims is correct too. The driver installer cannot test if the new configuration is going to be working, and it can happen that the installed driver crashes the X server the next time it is started. That would mean the user starts out with a working X server, then does a driver update, restarts his machine and finds himself in textmode or with a black screen.
Of course this is not really desirable either.
The packages distributed with Linux distributions like SuSE or RedHat are not affected by this problem because they can do the installation steps that are most likely to fail (compiling the sources and linking the loadable module) on the maintainer's system and ship the readymade module as part of the package.
This means the chance that your X server would not work after the upgrade is less with that method than with the full Nvidia driver installer.
It would be possible to check for some of the problem areas, e.g. by compiling a "test module" and trying to load it to see if the components required for that (compiler, headerfiles, linker etc) are present on the system and have the correct version.
It could probably not be made 100% foolproof.
So in the end, the decision is between:
- require everyone to learn how to shutdown X and perform the driver operation in textmode, with full recovery in case of installation problems
- perform a "hope for the best" installation from within X, and require those that encounter a failure to learn how to remedy it without re-installing their entire system
Apparently Nvidia have chosen the first alternative and the package distributors have chosen the second.