CentOS is extremely popular among startups. It lets you directly use RPMs, which many software publishers distribute on their own (not the case for debs, often), and gives you an upgrade path to buy RHEL when you want someone to yell at and not throw away all your automation.
I’m not trying to start a flame war here (honest), but among most “usual web” ops folks I know, the opposite of what you’re suggesting seems to hold and Debian/Ubuntu are looked at as an odd choice. It’s probably hire #1 going with what they know, more than anything, and it could very well be selection bias regarding the people I know. I’d love to see stats.
I’ve been working with CentOS or OEL in my own roles for several years now, and I’ve never chosen it. (Not saying I wouldn’t, just that it’s been there when I get there.)
There are just as many publishers that supply debs and not rpms. It really depends on what you're after.
But if you look at the usage, north america is generally more redhat-family and europe is generally more debian-family, even in the SuSE patch that is Germany...
Oracle Linux is the only direct upgrade path for CentOS (afaik).
A full reinstall is required to move from CentOS to RHEL. Oracle has a procedure to directly convert CentOS, RHEL, and Scientific Linux into a supported Oracle Linux system.
KSplice is the most common reason why this conversion is required and mandated. If downtime can no longer be tolerated for upgrades to openssl/glibc/vmlinuz, this is the only available path.
I’m not trying to start a flame war here (honest), but among most “usual web” ops folks I know, the opposite of what you’re suggesting seems to hold and Debian/Ubuntu are looked at as an odd choice. It’s probably hire #1 going with what they know, more than anything, and it could very well be selection bias regarding the people I know. I’d love to see stats.
I’ve been working with CentOS or OEL in my own roles for several years now, and I’ve never chosen it. (Not saying I wouldn’t, just that it’s been there when I get there.)