Linux – the best Linux distro for a php web server?

CentOS is based on Red Hat Enterprise Linux, which is built for businesses to use in servers. As such, it values stability far more than the latest bleeding edge features which may or may not work properly. So it rarely has the latest and greatest versions of anything. The preference is instead for the version that's been around the block a few times, and had all the kinks worked out.

Now, that being said, RedHat does back port patches. So any bugs or vulnerability issues that are fixed in later versions of Apache will be applied to RedHat's version. So you have the security of the latest patches, combined with the stability of a well known, and well tested software version. That's exactly what businesses are looking for.

If you really want the latest version of something, you still have options. You can A) compile it yourself. B) Get a distribution more aimed at bleeding edge versions. Or C) use a repository other than the official RedHat ones, that may have newer versions of software.

It's a best practice to have the owner be whatever limited user account is used for uploading/managing the files on the server. The group is often the account that php is running under, so in this case apache would be correct. The other permissions should be set to nothing, as they are. You are close to perfect.

If you have a situation where multiple accounts may be modifying/editing the files you can creat a cron script that chowns the dir recursively every hour or so to maintain correct ownership. The same technique works to keep the permissions correct as well.

Also, you may want to modify the umask of the limited user account that has ownership to be inline with your permission scheme.