[CentOS] how to convert 7 cd iso images into one dvd image?

Sat Jan 15 02:05:26 UTC 2011
John R Pierce <pierce at hogranch.com>

On 01/14/11 5:29 PM, Kenneth Wolcott wrote:
> Home ISP blocking bittorrent; company now blocks bittorrent.
> I want/need an old release (CentOS 5.2) to install as a VirtualBox guest.
> I suppose I could install from the cd iso images, but it is a pain to
> virtually eject and remount cd iso images during the install :-(
> So, is there a technique or an open source tool that will create a dvd
> iso given the cd iso images?

I've seen the DVD ISO files on select mirrors.    it can be difficult to 
reliably transfer a > 4GB file over http/ftp