groupinstall Base don't woks :(

Hello,

I'm following this article:
http://www.redhat.com/magazine/004feb05/features/virtualization/

And this command don't works for me:
yum --installroot=/mnt -y groupinstall Base

Loading "installonlyn" plugin
Setting up Group Process
Setting up repositories
livna                                                                [1/7]
http://rpm.livna.org/fedora/Null/x86_64/repodata/repomd.xml: [Errno 14] HTTP 
Error 404: Date: Wed, 25 Oct 2006 17:54:45 GMT
Server: Apache/2.0.52 (CentOS)
Content-Length: 315
Content-Type: text/html; charset=iso-8859-1
Trying other mirror.
http://livna.cat.pdx.edu/fedora/Null/x86_64/repodata/repomd.xml: [Errno 12] 
Timeout: <urlopen error timed out>
Trying other mirror.
http://wftp.tu-chemnitz.de/pub/linux/livna/fedora/Null/x86_64/repodata/repomd.xml:
 [Errno 14] HTTP Error 404: Date: Wed, 25 Oct 2006 18:08:01 GMT
Server: Apache/2.0.52 (Red Hat)
Content-Length: 384
Content-Type: text/html; charset=iso-8859-1
Trying other mirror.
http://ftp-stud.fht-esslingen.de/pub/Mirrors/rpm.livna.org/fedora/Null/x86_64/repodata/repomd.xml:
 [Errno 14] HTTP Error 404: Date: Wed, 25 Oct 2006 18:08:01 GMT
Server: Apache/2.2.3 (Fedora)
Vary: accept-language,accept-charset
Accept-Ranges: bytes
Connection: close
Transfer-Encoding: chunked
Content-Type: text/html; charset=iso-8859-1
Content-Language: en
Trying other mirror.
http://mirror.atrpms.net/livna/fedora/Null/x86_64/repodata/repomd.xml: [Errno 
14] HTTP Error 404: Date: Wed, 25 Oct 2006 18:08:02 GMT
Server: Apache/2.2.2 (Fedora)
Content-Length: 324
Connection: close
Content-Type: text/html; charset=iso-8859-1
Trying other mirror.
ftp://mirrors.tummy.com/pub/rpm.livna.org/fedora/Null/x86_64/repodata/repomd.xml:
 [Errno 4] IOError: [Errno ftp error] timed out
Trying other mirror.
Cannot open/read repomd.xml file for repository: livna
failure: repodata/repomd.xml from livna: [Errno 256] No more mirrors to try.
Error: failure: repodata/repomd.xml from livna: [Errno 256] No more mirrors to 
try.


Any ideas?
Thanks!