Question on Network Performance Optimization

Right now, I'm trying to set up a fast network backup solution. I've got a couple of backup servers configured to use a nearline disk storage array via NFS.

The backup servers have a 10Gbps failover interface-group (bonding mode 1) to handle client data ingest. They also have four, 1Gbps interfaces - currently configured into a LACP interface-group (bonding mode 4) - connected to the nearline storage device's network. That is, ingest is on one network segment and backup storage is on a different segment with the backup servers bridging the two networks.

My nearline storage device has two 10Gbps interfaces. They're currently configured into a failover interface-group. I could conceivably change them to be two, independent NICs (each with their own IP but on the same network segment) and then use a director application to handle individual path failures.

What I need to sort out is:

• is LACP my best option for the backup servers' 1Gbps interface-grouping?
• is acitve-passive failover my best performance option for my nearline device?

Additional data points:

• the NFS network, while using 10Gbps switching infrastructure has been rate-limited to 5Gbps.
• I've got two backup servers with identical asymmetrical network configuration.

Any practical experience anyone can bring to bear or am I stuck twiddling knobs to find the most optimal data-flow configuration?