Linux : Keep Cache and Set proxy server for yum

in /etc/yum.conf

cachedir=/export/errata
keepcache=1

proxy=http://a.b.c.com:8080

The following is the URL for Oracle OVM repo
 baseurl=http://public-yum.oracle.com/repo/OracleVM/OVM3/3x_latest/x86_64/

Linux : Set Proxy Server for wget

vi ~/.wgetrc

and add the following

use_proxy = on
https_proxy=https://a.b.c.com:8080/
http_proxy=http://a.b.c.com:8080/