(this post will appear in our virtual private server blog as well)
Abstract/Summary – basics only
These days, the most prominent Linux flavours are Red Hat, CentOS, Debian, Fedora, SUSE/SLES, and Ubuntu. The number of variants of these flavours is legion, the main distinction here, however, is that Red Hat is a fully commercial branch, whereas the others are available free of charge.
Red Hat is closely related to CentOS and Fedora, and while avoiding too technical an explanation, in layman terms CentOS can be seen as the “free” version of Red Hat, Fedora as the “next generation Red Hat”. There are a lot of caveats with these metaphors, but they help to get an overall idea. Debian and Ubuntu are independent (similar to some extent) flavours with their own community. Ubuntu has gained a lot of popularity recently due to its cloud abilities. SUSE was originally independent and started off in Germany, but has been bought by Novell and has seen a decline in community lately.
Red Hat and CentOS are more conservative in their application of packages and in their approach of going for the latest in everything. This is not necessarily a bad appoach at all – a huge number of commercial, high performance, and mission critical applications are specifically tuned for Red Hat, based on our own Linux experience since 1992, starting with Slackware, we identified Red Hat and CentOS as the leading Linux flavours for our own server environment (this is not a strictly objective judgement per se, as we of course need to evaluate our own needs first, and we encourage digressing opinions).
Red Hat and CentOS are ideal solutions for virtualisation, too. Both offer similar technologies, though we tend to go for KVM with Red Hat, and openVZ with CentOS (openvz will also run on Fedora, by the way). KVM (kernel based virtual machine) employs a different concept than openVZ, and allows running guests in a way such that the guest does not really know it is a guest only. That gives you a chance to, say, run a Windows server as a guest system on a Red Hat (or, rather, KVM) host – openVZ will only support Linux guests, and the ones we have best experience with are CentOS, Debian, Fedora, Ubuntu, and to some extent SUSE.
When it comes to control panels, we have excellent experience with CentOS + cPanel/Plesk, and Debian + Plesk. These setups pretty much work out of the box, and wont give you any hassles in a live environment.