I have been using several VMs for simulating a multi-node environment. Most of my VMs are CentOS.
After installing CentOS 6.4 I got the following error when I tried “yum update“:
Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was 14: PYCURL ERROR 6 - "Couldn't resolve host 'mirrorlist.centos.org'" Error: Cannot find a valid baseurl for repo: base
To fix this error I updated NM_CONTROLLED to “no” in the file /etc/sysconfig/network-scripts/ifcfg-eth0
After this I restarted the network interface using the following commands:
ifdown eth0 ifup eth0
After doing the above the yum update started working.
Hope this helps.