Keywords: nfs

Next: Other Factors Up: The Kernel-Space NFS Server Previous: Moderate Load

### Heavy Load

For the heavy load, we set the initial load to 800 and increment the load by 800 at each run:

Run | # of Server | # of | # of Processes | Load | Throughput | Response Time
| Threads | Clients | Per Client | (Ops/Sec) | (Ops/Sec) | (Msec/Op)
1 | 1 | 5 | 4 | 800 | 356 | 56.6
2 | 1 | 5 | 4 | 1600 | 212 | 97.8
3 | 1 | 5 | 4 | 2400 | 162 | 127.5
4 | 1 | 5 | 4 | 3200 | 138 | 151.9
1 | 2 | 5 | 4 | 800 | 569 | 36.8
2 | 2 | 5 | 4 | 1600 | 381 | 54.8
3 | 2 | 5 | 4 | 2400 | 311 | 67.5
4 | 2 | 5 | 4 | 3200 | 264 | 78.6
1 | 4 | 5 | 4 | 800 | 782 | 27.4
2 | 4 | 5 | 4 | 1600 | 594 | 35.9
3 | 4 | 5 | 4 | 2400 | 494 | 42.8
4 | 4 | 5 | 4 | 3200 | 422 | 49.8
1 | 8 | 5 | 4 | 800 | 799 | 6.9
2 | 8 | 5 | 4 | 1600 | 1125 | 19.4
3 | 8 | 5 | 4 | 2400 | 907 | 23.9
4 | 8 | 5 | 4 | 3200 | 775 | 27.7
1 | 16 | 5 | 4 | 800 | 801 | 6.1
2 | 16 | 5 | 4 | 1600 | 1539 | 14.2
3 | 16 | 5 | 4 | 2400 | 1190 | 18.9
4 | 16 | 5 | 4 | 3200 | 967 | 22.8

It is quite clear that under the heavy load, the NFS server performance benefits tremendously when the number of the server threads was increased from 1 to 8. When it is above 8, the performance gain was not as significant as the lower thread count.

Overall, the SFS benchmarks show that

- The kernel-space NFS server is a major step forward in the Linux NFS server implementation. Its interoperability and performance are way beyond the old NFS server running in user-space.

- The number of kernel NFS server threads will affect the server performance. In general, the more, the better.

- Under the light load, the performance gain from increasing the number of server threads is not very significant.

- Under the moderate load, 8 server threads seem to work best for our server hardware configuration.

- Under the heavy load, the performance gain from increasing the number of server threads is significant even at 16. However, 16 server threads take significant kernel sources.

For our specific server hardware setup, 8 kernel NFS server threads strike a balance between performance and resource usage.

To further study the Linux NFS server performance, we need to run the benchmarks on

- Different number of CPUs.

- Different number of SCSI controllers.

- Different number of harddrives.

- RAID storage.

- More RAM.

- Gigabit Ethernet.

Next: Other Factors Up: The Kernel-Space NFS Server Previous: Moderate Load