Great question, Jeff, I recently saw an answer to your question. Here it is:
Yes, the PowerLinux 7R2 supports dual VIO servers, even though it does not support the split backplane. Since there is no split backplane support, the internal disk can support boot disk for a single VIO server only. Boot disk for the second VIO server, or both VIO servers, can be provided via SAN disk. If the 7R2 is model L2S, boot disk for the second VIO server, or both VIO servers, can be provided via the EXP24S. In this scenario, the EXP24S must be attached to the L2S via PCIe adapter, not via the external SAS port provided on features ELOV and ELOY.
Note: Dual VIO servers are not supported with IVM. This functionality requires an HMC.
For those of you who like TechDocs, this answer was posted under Document ID FQ131260.