This section (see Table 5-1) lists the actions to perform when you encounter a tuning problem.
Table 5-1 General Troubleshooting Tuning Problems and Actions to Perform
Command/Tool |
Command Output/Result |
Action |
---|---|---|
netstat -i |
Collis+Ierrs+Oerrs/Ipkts + Opkts > 2% |
Check the Ethernet hardware. |
netstat -i |
Collis/Opkts > 10% |
Add an Ethernet interface and distribute the client load. |
netstat -i |
Ierrs/Ipks > 25% |
The host may be dropping packets, causing high input error rate. To compensate for bandwidth-limited network hardware: reduce the packet size; set the read buffer size, rsize and/or the write buffer size wsize to 2048 when using mount or in the /etc/vfstab file. See "To Check the Network" in Chapter 3, Analyzing NFS Performance. |
nfsstat -s |
readlink > 10% |
Replace symbolic links with mount points. |
nfsstat -s |
writes > 5% |
Install a Prestoserve NFS accelerator (SBus card or NVRAM-NVSIMM) for peak performance. See "Prestoserve NFS Accelerator" in Chapter 4, Configuring the Server and the Client to Maximize NFS Performance. |
nfsstat -s |
There are any badcalls. |
The network may be overloaded. Identify an overloaded network using network interface statistics. |
nfsstat -s |
getattr > 40% |
Increase the client attribute cache using the actimeo option. Make sure the DNLC and inode caches are large. Use vmstat -s to determine the percent hit rate (cache hits) for the DNLC and, if needed, increase ncsize in the /etc/system file. See "Directory Name Lookup Cache (DNLC)"in Chapter 4, Configuring the Server and the Client to Maximize NFS Performance. |
vmstat -s |
Hit rate (cache hits) < 90% |
Increase ncsize in the /etc/system file. |
Ethernet monitor, for example: SunNet Manager SharpShooter, NetMetrix |
Load > 35% |
Add an Ethernet interface and distribute client load. |