NFS latency optimization works in the following ways:
Directory index pre-fetching.
File read-ahead and write-behind.
NFS latency optimization does not work if:
The NFS version spoken is not NFS version 3.
Figure 8.27. NFS optimization does not work for NFS version 4
SH sport[24148]: [SunRpc-CFE/SunRpcParser.WARN] - {10.0.1.1:1023 192.168.1.1:2049} NFSv4 \ traffic detected between client 10.0.1.1 and server 192.168.1.1 SH sport[24148]: [SunRpc-CFE/SunRpcParser.WARN] - {10.0.1.1:1022 192.168.1.1:2049} NFSv4 \ traffic detected between client 10.0.1.1 and server 192.168.1.1 statsd[23848]: [statsd.NOTICE]: Alarm triggered for rising error for event nfs_v2_v4
If the NFS Authentication method is set to Kerberos authentication.
Figure 8.28. NFS optimization does not work when using Kerberos authentication
SH sport[24148]: [SunRpc-CFE/NfsV3Parser.NOTICE] - {10.0.1.1:1023 192.168.1.1:2049} SunR \ pcParser: Client Call has an authenticationflavor which we do not support. Shutting La \ tencyOptimization for this connection.
NFS Funkiness:
There is a 15 second directory meta-data timer[SOURCE: NFS standard] which can show files which have been removed or not show files which have been created on other machines. This is NFS behaviour, not Steelhead appliance specific behaviour.