On Mon, 9 Dec 2002, Garrett Burke wrote:
I'm wondering if anyone out there has experience with running NFS with filers over long distances - of the order of 10s of KM.
Not recently, but we currently have an electronic fax application that runs on a W2K server in Calgary, saves decoded TIFFs over CIFS to a filer in Toronto, where a UNIX box runs ImageMagick over it and does funky stuff to present it to the user via Apache. CIFS seems to be chattier and much more finicky than NFS in terms of less-than-ideal network conditions too. I don't know what the wire distance is, but it is probably in the 3000 km range.
I'm particularly interested to find out experiences when bandwidth was and wasn't an issue. For example, running at 34Mbs/155Mbs against running over GigE. Was tweaking the NFS request size required? Was TCP used and if so was it because pkt loss was impacting NFS performance? Did latency become an issue?
I find that bandwidth tends to be less of an issue than latency and packet loss. With 6000 km for a round trip, speed of light becomes noticeable (20 ms right there). At only 10 km, you should be able to run Gigabit Ethernet over fiber without too much complexity slowing things down... sub-millisecond latency should be possible, although I don't have anything in that configuration right now to back up that assertion.