/etc/rc.d/rc.sysinit invokes fsck with -C by default. If you are running your server with a serial console (9600 bps is the industry standard), this takes a _long_ time (like, half an hour!), since fsck updates the display _way_ too often. The workaround is of course to manually remove the -C from /etc/rc.d/rc.sysinit.
Fixed in the latest initscripts packages - -C is not used over serial console.