Problem from email:

I setup the repos file as described in the above URL and get the following error,

[root@ldas-pcdev4 yum.repos.d]# yum search pegasus
http://pegasus.isi.edu/wms/download/3.1/yum/rhel/6.1/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404"
Trying other mirror.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: Pegasus31. Please verify its path and try again