IntroductionThe commands specified in the answers to this question and this documentation have been applied to install NCDU on Scientific using EPEL without success.According to this documentation it should be possible to install ncdu using EPEL.setup EPEL repo$ sudo wget http://download.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm$ sudo rpm -ivh epel-release-6-8.noarch.rpmwarning: epel-release-6-8.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEYPreparing...                ########################################### [100%]        package epel-release-6-8.noarch is already installedinstall ncdu$ sudo yum install ncdu -yLoaded plugins: securityError: Cannot retrieve repository metadata (repomd.xml) for repository: epel. Please verify its path and try againQuestion: How to install NCDU on Scientific from EPEL?
Install NCDU on Scientific from EPEL
yum;rpm;repository;scientific linux
Your approach looks correct in terms of setting up the EPEL repository and attempting to intsall NCDU. I even confirmed that hte NCDU RPM is in fact in that repository:http://ftp.linux.ncsu.edu/pub/epel/6/x86_64/ncdu-1.7-1.el6.x86_64.rpmSo this particular issue looks like it has little to do with the RPM, and more to do with the setup of the EPEL repository on your system.The quick answerIf you just want to install NCDU you can simply do this to manually install the RPM from that repository:$ sudo yum localinstall \    http://ftp.linux.ncsu.edu/pub/epel/6/x86_64/ncdu-1.7-1.el6.x86_64.rpmThe long answerIf you'd like to figure out what's wrong with your YUM setup I'd first start with running the command yum clean all.After that I'd double check that the .repo files for the EPEL repo are in fact setup correctly undre /etc/yum.repo.d/.I'd also remove and re-install the EPEL RPM file:$ sudo yum remove epel-release$ sudo yum localinstall epel-release-6-8.noarch.rpm