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Re: Best utilizing fat long pipes and large file transfer

  • From: Michal Krsek
  • Date: Fri Jun 13 02:42:56 2008

Hi Sean,
from thursday, we have copied some ~300 GB packages from Prague to San Diego (~200 ms delay, 10 GE flat ethernet end machines connected via 1GE) files using RBUDP which worked great.


Each scenario needs some planning. You have to answer several questions:
1) What is the performance of storage subsystem (sometimes you need to connect external harddrives or tape robot)
2) How many files you need to transfer?
3) How big are these files?
4) What is the consistency scenarion (it is file consistency or package consistency)?


In example, I've sent some film data. Lot (~30.000) of 10 MB DPXes. Consistency was package based. Harddrives have been at the beggining connected via iLink (arrived on this media), then moved to eSATA (went to shop, bought another drive and connected it into export machine). Main tuning for RBUDP has been to buy another harddrive and tar these files.

      Regards
         Michal

Hi,

I'm looking for input on the best practices for sending large files over a long fat pipe between facilities (gigabit private circuit, ~20ms RTT).
I'd like to avoid modifying TCP windows and options on end hosts where possible (I have a lot of them). I've seen products that work as "transfer stations" using "reliable UDP" to get around the windowing problem.


I'm thinking of setting up servers with optimized TCP settings to push big files around data centers but I'm curious to know how others deal with LFN+large transfers.

thanks,
Sean