[CentOS] Disc layout advice

>You don't run pvcreate on lvm partitions.  You run pvcreate on the block
>devices that will be added to the volume groups.

You sure can run pvcreate on a partition, for example /dev/cciss/c0d0p1
instead of /dev/cciss/c0d0 and the use of it for example, creating a
partition of "Type" LVM so that it's obvious what's going on:)

man pvcreate

/snip
Each PhysicalVolume can be a disk partition, whole disk, meta device, or loopback file.
/snip

jlc