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As you might expect, CentOS 7 has its package differences from CentOS 6. What does looks like from the ground, though? There have been a number of changes, as you might expect.

Well, let's start with my base-level kickstart file which sets up a fairly minimal system:

Naturally, if you're going to use this as a template, you would make changes as appropriate to your own system (particularly, I'd imagine, the disk configuration).

A couple of notes:

• You may notice that I don't do much in the way of system configuration here. That's because it makes more sense to use a configuration management tool to configure systems, so the base kickstart configuration file tries to target system-level stuff.
• I use a multi-partition layout to "sandbox" the partitions that have a potential to grow out of control. I don't want /var or /tmp filling up to bring the entire system down. As a bonus, since this is a virtualized system, this allows me to grow the three partitions as needed relatively easily (since they're all located at the end of their respective disks).
• This is a base kickstart configuration, so other derived configurations will naturally have additional packages and post-install instructions.

Packages that have been removed from CentOS 7 (notes sometimes pulled from this page):

Meanwhile, the number of added packages is fairly considerable:

Disk usage is comparable to CentOS 6, even with the additional packages (many of which I expect are a result of refactoring). And several of those new packages will require further investigation, to see how well the new functionality works.

I've decided to finally get around to set up kickstart configuration files for my system images, since I've started investigating migrating over to CentOS 7. Kickstart, if you're not familiar with it, is a method of automating Linux installation and configuration, and is largely centered around the Red Hat-based distributions. While I was setting all of this up, I decided to also investigate whether it was worth switching from CentOS to Ubuntu Server, seeing as Ubuntu usage has passed CentOS and RHEL usage according to W3Techs (I suppose I could have looked at Debian as well, but for whatever reason it doesn't particularly appeal to me - possibly because it's not as marketable a job skill, for all that I don't really do this for a career?).

That said, I decided not to, for a couple of reasons:

• The difference in how well they're documented is huge. Red Hat has a tremendous amount of documentation on setting up a kickstart installation compared to Ubuntu's preseed documentation (which seems to boil down to: take this undocumented file and it should work). Somewhat ironically, Debian has considerably better documentation.
• Red Hat's installation process generates a kickstart configuration file (/root/anaconda-ks.cfg) that you can immediately turn around and feed back into a kickstart installation to get the same result, whereas the Debian documentation notes that their equivalent (debconf-get-selections --installer; debconf-get-selections) doesn't actually quite work (and I would expect that Ubuntu would follow in the same footsteps).
• And, of course, I'm still better and more comfortable with Red Hat-based distributions than Ubuntu distributions, which matters for what is effectively a production deployment.

P.S. Yes, Ubuntu can also support kickstart installations, but it's a hacky process. I don't care that much.