Tuning for Kernel NFS backend on AFM and AFM DR

If AFM communication uses the NFSv3 protocol, for peak performance, tune the gateway NFS servers that host home exports and the gateway servers that support cache/primary filesets.

Most of these tuning parameters require at least the AFM client to be restarted. Ensure that the NFS server is not mounted. Unlink the AFM fileset or stop GPFS or IBM Storage Scale on the gateway node.

Tuning for 1 GigE networks is different from tuning 10 GigE networks. For 10 GigE, all settings need to be scaled up, but not necessarily by a factor of 10. Many of these settings are affected when a server is restarted. Therefore, each time a server restarts, the settings must be reset. The TCP buffer tuning is required for all 10 GigE links and for 1 GigE links where the value of RTT is greater than 0.