On Wed, Aug 17, 2011 at 2:00 PM, Bakul Shah <ba...@bitblocks.com> wrote: > On Wed, 17 Aug 2011 13:09:47 +0300 =?UTF-8?B?QXJhbSBIxIN2xINybmVhbnU=?= > <ara...@mgk.ro> wrote: >> Hello, >> >> I'm looking for advice on how to build a small network of two file >> servers. I'm hoping most servers to be Plan9, clients are Windows and >> Mac OS X. >> >> I have 2 houses separated by about 40ms of network latency. I want to >> set some servers in each location and have all data accessible from >> anywhere. I'll have about 2TB of data at each location, one location >> will probably scale up. > ... >> Is 9p suitable for this? How will the 40ms latency affect 9p >> operation? (I have 100Mbit). > > With a strict request/response protocol you will get no more > than 64KB once every 80ms so your throughput at best will be > 6.55Mbps or about 15 times slower than using HTTP/FTP on > 100Mbps link for large files. [John, what was the link speed > for the tests in your thesis?] >
10 Mbps was the bottleneck--I had a 100 Mbit switch connected to one side of the Linux gateway and a 10 Mbit hub on the other. I know a 10 Mbit hub is not modern networking equipment, but the only traffic on it was the tests, and I also figured that 1. You're not likely to do much better on a cross-country net link anyway, and 2. The HTTP tests would suffer just as badly :) If you'd like to Dare to Be Stupid, you can download my source and run both servers with streaming enabled, then make some sort of client-side caching filesystem which can stream from the remote (40 ms away) server on behalf of applications, avoiding the necessity of re-coding all your applications to understand streaming. Or just serve your files over SMB, NFS, or HTTP. I guess I didn't check, but if you *have* 2 TB of data but don't plan to routinely *access* that much of it at any given time, you can probably get away with using 9P. I do not think there is any way a fossil+venti or kenfs file server serving 9P will outperform your Solaris server. Not with our current software. The way I use it, Plan 9 and 9P are "fast enough", but for serious data transfer over such a high-latency link they won't cut it. Plan 9 + HTTP would be a reasonable option if you just want to share movies and music between your houses, I suppose. John
