Date: Tue, 11 Dec 2007 12:58:45 +0100 (CET) From: Konrad Heuer <kheuer2@gwdg.de> To: Wojciech Puchar <wojtek@wojtek.tensor.gdynia.pl> Cc: freebsd-questions@freebsd.org Subject: Re: why nfs is so slow? Message-ID: <20071211125137.T46172@gwdu60.gwdg.de> In-Reply-To: <20071211120127.F1536@wojtek.tensor.gdynia.pl> References: <20071211120127.F1536@wojtek.tensor.gdynia.pl>
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On Tue, 11 Dec 2007, Wojciech Puchar wrote: > i'm getting about 6MB/s with NFS (100Mbit cross-connect ethernet), while over > 9.5 by FTP. > > nfs is set to work over TCP. To my mind, this is because NFS is stateless because of being designed to share filesystem on a whole local network. Thus, every remote procedure call (the basic NFS operation) is self contained. Thus, every single read request causes the server to open the file, to read the number of bytes requested, and to close the file. If you compare this to a typical peer-to-peer ftp session, the overhead is obvious. On the other hand, ftp is a very special application. Best regards Konrad Heuer GWDG, Am Fassberg, 37077 Goettingen, Germany, kheuer2@gwdg.de
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