Note: The directions at "http://wiki.openvz.org/Install_OpenVZ_on_a_x86_64_system_Centos-Fedora#STEP_12" did not quite work for me as ".gpgkeyschecked.yum" gets created in the yum-cache directory as well and is not available to the containers. The workaround below worked for me.
To share the vzyum cache directory between various containers. Edit "/etc/auto.master" to include the following:
/vz/root/{vpsid}/var/cache/yum-cache /etc/auto.vzyum
Include one line for each installed or planned VPS, replacing {vpsid} with the adequate value.
Then, create "/etc/auto.vzyum" file with only this line:
share -bind,ro,nosuid,nodev :/var/cache/yum-cache/share
Restart the automounter daemon.
Edit "/vz/template/centos/5/x86_64/config/yum.conf" and change cachedir location:
cachedir=/var/cache/yum-cache/share
Create the corresponding cachedir:
mkdir /var/cache/yum-cache/share
Test with:
vzyum {vpsid} clean all
This should create all of the yum cache directory at "/var/cache/yum-cache/share" location and should be available to the openvz container via bind mount.