In the past, I’ve used our local mirror of the CentOS yum repository to kickstart machines booted using PXE; apparently, this no longer works with CentOS 5.1, although it did with 5.0. If you attempt to do so, after the initial PXE boot, you get the following message:
The CentOS installation tree in that directory [...]
adm amazon amazon aws aws cloud comstar deduplication ebs ec2 emc esx fas2020 fibre channel firefox fishworks flash hp hsm hyper-v iscsi kvm limits linux microsoft netapp nfs nfsv4 opensolaris patching s3 sam-qfs solaris ssd sun sxce timekeeping ubuntu virtualization vmware vmware esx vmware freebsd wafl windows xen zfs