Are you able to add another NIC to the server? Then you could have a 2 port LAG to each switch. 
Good day all  I have a Windows 2008 R2 File Server using Broadcom Netxtreme II NICs. I have Teaming configured using the BroadCom Advanced Control Suite 4 . The two 5448's are configured using port-channels to pass traffic to a pair of Dell (Force 10) S25's. I want to team my server for Load Balancing across the two 5448's using LACP. Can anyone give me a config on the switch ports that my Server would connect to. It is one connection per switch
Two 5448's using LACP