Reini (and Steven),
Okay, I get. This benchmark you introduced below compares rsync on two variables: copy speed locally vs over the network, and copy speed for copies onto indentical target files vs different target files. And your benchmark showed that rsync was faster for copies onto pre-existing target files -- just as rsync is supposed to be.
I just ran the same benchmark on my side and I get exactly the opposite results. For what it's worth, here's what I got. I started with two different binary files (based on different mp3's) each of size 434006.
%[local copy, target file is different ] %time rsync test1.mp3 test2.mp3
real 0m6.422s user 0m0.430s sys 0m1.431s
%[local copy, target file is the same ] %time rsync test1.mp3 test1-same.mp3
real 0m6.523s user 0m0.300s sys 0m1.261s
%cp test2.bak test2.mp3 %[network copy, a pure copy with scp for benchmark] %time scp test2.mp3 $TEST:
260.6KB/s (calculated average) real 0m16.257s user 0m0.510s sys 0m1.091s
%[network copy, target file is different ] %time rsync test1.mp3 $TEST:test2.mp3
real 0m13.797s user 0m1.421s sys 0m1.250s
% (network copy, files are 100% the same) % (repeated twice to guarantee target file is there) %time rsync test2.mp3 $TEST:test2.bak
real 0m28.329s user 0m1.390s sys 0m4.766s
%rsync --version rsync version 2.6.2 protocol version 28 ssh $TEST rsync --version rsync version 2.6.2 protocol version 28 $ ssh -V OpenSSH_3.8.1p1, OpenSSL 0.9.7d 17 Mar 2004 $ ssh $TEST ssh -V OpenSSH_3.7.1p1, SSH protocols 1.5/2.0, Open SSL 0.9.7d 17 Mar 2004 (but ssh -v reports TEST's sshd server is responding with OpenSSH_3.6.1p1+CAN-2003-0693, SSH protocols 1.5/2.0, Open SSL 0x0090702f ) $ uname -r 1.5.10(0.116/4/2)
As you can see, my network copy onto an identical waiting file is taking almost twice as long as a network copy onto a _different_ waiting file, and is also substantially slower than a pure copy. So I'm experiencing a net rsync slowdown rather than a speedup.
Is it the processor? Thorsten Kampe And Steven Hartland suggested the problem is in effect that my computer is too slow, and that I should turn off all checksumming. I seem to have more bandwidth to my TEST machine than you, so I suppose my processor might be the bottleneck for me but not for you, which would explain our different results. How fast was your machine?
Or Is it cygwin? I notice that the enormous slowdown for the network copy onto an identical target is all appearing in the 'real' component of the time's timing report, and that there's a bit of extra time in 'sys' but other than that there's nothing to account for it. I'm not sure how to interpret that. Would cygwin-specific delays appear in 'sys'? In other words, does this mean the checksums are using up all the time, and confirm that my processors are too slow to benefit from rsync?
Best wishes, Alexis
Reini Urban wrote:
So check if the net overhead in the cygwin version is broken? Could be easily tested out with two local files:
head -c 2100000 < /dev/random >test1.mp3 head -c 2100000 < /dev/random >test2.mp3 cp test1.mp3 test1-same.mp3 cp test2.mp3 test2.bak time rsync test1.mp3 test2.mp3
real 0m0.518s user 0m0.201s sys 0m0.171s
time rsync test1.mp3 test1-same.mp3
real 0m0.524s user 0m0.154s sys 0m0.263s
RSYNC_RSH=ssh TEST=othermachine cp test2.bak test2.mp3 time scp test2.mp3 $TEST:
63.2KB/s real 0m36.619s user 0m0.170s sys 0m0.233s
# 100% different $ time rsync test1.mp3 $TEST:test2.mp3 Server is very old version of rsync, upgrade recommended.
real 0m37.162s user 0m0.388s sys 0m0.202s
# 100% same $ time rsync test2.mp3 $TEST:test2.bak Server is very old version of rsync, upgrade recommended.
real 0m7.298s user 0m1.201s sys 0m2.217s
6x faster than scp, with same data. 0.5s (1.4%) slower than scp, with complete random data.
$ rsync --version rsync version 2.6.2 protocol version 28 $ ssh $TEST rsync --version rsync version 2.4.6 protocol version 24 $ ssh -V OpenSSH_3.8.1p1, OpenSSL 0.9.7d 17 Mar 2004 $ ssh $TEST ssh -V OpenSSH_3.7.1p2, SSH protocols 1.5/2.0, OpenSSL 0.9.6c 21 dec 2001 $ uname -r 1.5.10(0.116/4/2) -- Reini Urban http://xarch.tu-graz.ac.at/home/rurban/
I see the final result you
-- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/