RHEL Yum

Yum Management

By default, Redhat repo does not contain php-mbstring in Amazon AWS. php-mbstring is required for phpMyAdmin, wordpress, etc.
To Install php-mbstring

yum repolist all
# found rhui-REGION-rhel-server-optional in the list
yum-config-manager --enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional
yum search php-
yum install php-mbstring

Yum Add or Disable Repo

#Add
yum-config-manager --add-repo repository_url

Disable repo

see also

http://www.if-not-true-then-false.com/2010/yum-remove-repo-repository-yum-disable-repo-repository/