cd /mnt
mkdir iso
mkdir yum
cp xxx.iso /mnt/iso
mount -o loop -t iso9660 /mnt/iso/xxx.iso /mnt/yum
cd /etc/
mv yum.repos.d yum.repos.d.bak
mkdir yum.repos.d
cd yum.repos.d
vi local.repo
[local_server]
name=this is a local source
baseurl=file:///mnt/yum
enable=1
gpgcheck=0
yum clean all
yum makecache