Do you need more mirrors that also serve updates? A review of our access logs indicated very few .rpm files being served. A little more poking around showed that http://mirror.pnl.gov/centos shows up in http://mirror-status.centos.org/ and http://www.centos.org/modules/tinycontent/index.php?id=30 but not (e.g.) http://mirrorlist.centos.org/?release=5&arch=i386&repo=os . Also, I confirmed that editing /etc/yum.repos.d/CentOS-Base.repo to use (e.g.) baseurl=http://mirror.pnl.gov/centos/$releasever/os/$basearch/ instead of mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os ...works well to point yum at our new mirror for updates. Please accept my apologies for wasting everyone's time if I've missed a FAQ, HOWTO or some other documentation on how the system works! Thank you, Bill Nickless