I have Windows OpenAFS client 1.7.1500 on a 32-bit machine with Windows XP and a 100 mbit/s network interface. Line rate between the client's port and the target AFS file server is ca. 96 mbit/s for UDP, in both directions (measured with iperf).
When I copy a single large file (ca. 1 GB) from the server to the client machine, I see a network utilization maxed at ca. 70 mbit/s, and timing the file transfer yields a similar overall rate. When I copy the same file from the client to the server, network utilization is 30 mbit/s at the maximum. Copying is always preceded by "fs flushall". My first question is why copying from the client to the file server is so much slower (by a factor of 2 or 3) than the other way around. The other question is why the network utilization, at least as reported under Windows, never approaches the line rate, even at quiet times, but rather stays below the caps of 70 and 30 percent. The client configuration parameters are: Cache size: 800 Mbytes Chunk size: 8192 Kbytes Daemons: 16 RxMaxMTU: 9000 Sec. level: 1 Server threads: 40 Stats: 20000 entries The machine has 3.45 Gbytes of RAM, and the paging file size is set at 5.3 Gbytes. I have consulted this post: http://blog.secure-endpoints.com/2008/03/i-want-my-openafs-windows-client-to -be.html but have not been able to improve the transfer rates by tweaking the client's parameters. Thank you for any help. Danko Antolovic Principal Scientist, Research Technologies, Indiana University
