Unable to add multi-entitlement feature for "Red Hat Enterprise Virtualization for Servers" using Subscription Manager

Issue

• A 2 socket 64 bit Red Hat Enterprise Linux 6.4 system cannot be subscribed with 2 quantities of "Red Hat Enterprise Virtualization for Servers, Standard (1 Socket)"

• The following error is observed:

[root@redhat]# subscription-manager list --available --all
+-------------------------------------------+
    Available Subscriptions
+-------------------------------------------+
Subscription Name:      Red Hat Enterprise Linux Server, Standard (1-2 sockets) (Unlimited guests)
SKU:                    RH0192098RN
Pool Id:                8a85f9813cf493fe013dca0ae1e2588d
Quantity:               4
Service Level:          Standard
Service Type:           L1-L3
Multi-Entitlement:      No
Ends:                   04/01/2014
System Type:            Physical

Subscription Name:      Red Hat Enterprise Virtualization for Servers, Standard (1 Socket)
SKU:                    RV0196478
Pool Id:                8a85f9833cf49557013d6184c05f13ee
Quantity:               2
Service Level:          Standard
Service Type:           L1-L3
Multi-Entitlement:      No
Ends:                   04/01/2014
System Type:            Physical


# subscription-manager subscribe --pool=8a85f9833cf49557013d6184c05f13ee --quantity=2
Multi-entitlement not supported for pool with id '8a85f9833cf49557013d6184c05f13ee'.