Network Performance Is Worse in a Logical Domain Guest Than in a Non-LDoms Configuration

Bug ID 6486234: The virtual networking infrastructure adds additional overhead to communications from a logical domain. All packets are sent through a virtual network device, which, in turn, passes the packets to the virtual switch. The virtual switch then sends the packets out through the physical device. The lower performance is seen due to the inherent overheads of the stack.

Workaround: Do one of the following depending on your server:

• On UltraSPARC T1 based servers, such as the Sun Fire T1000 and T2000, and UltraSPARC T2+ based servers such as the Sun SPARC Enterprise T5140 and T5240, assign a physical network card to the logical domain using a split-PCI configuration. For more information, refer to I/O Domains and PCI EXPRESS Buses in Logical Domains 1.2 Administration Guide.

• On Ultra SPARC T2 based servers, such as the Sun SPARC Enterprise T5120 and T5220 servers, assign a Network Interface Unit (NIU) to the logical domain.