Network connections
Use the nfsstat command to gather information about your network connections.
The nfsstat command determines whether you are dropping packets. Use the nfsstat -c and nfsstat -s commands to determine if the client or server is retransmitting large blocks. Retransmissions are always a possibility due to lost packets or busy servers. A retransmission rate of five percent or more is considered high.
The probability of retransmissions can be reduced by changing communication adapter transmit queue parameters. The SMIT menu can be used to change these parameters. For more information, refer to Available system management interfaces in Operating system and device management.
- Apply these values to NFS clients if retransmissions persist.
- All nodes on a network must use the same MTU size.
| Adapter | MTU | Transmit queue |
|---|---|---|
| Token Ring | ||
| 4 Mb |
1500 3900 |
50 40 (Increase if the nfsstat command times out.) |
| 16 Mb |
1500 8500 |
40 (Increase if the nfsstat command times out.) 40 (Increase if the nfsstat command times out.) |
| Ethernet | 1500 | 40 (Increase if the nfsstat command times out.) |
The larger MTU sizes for each token-ring speed reduce processor use and significantly improve read/write operations.