rsync very slow, but not a network issue

[Reini Urban]

Thorsten Kampe schrieb:

> * Alexis Gallagher (2004-07-12 19:46 +0200)
> 
>>I am finding that rsync+ssh is giving extremely slow file transfers. But 
>>this slowdown is hitting not when it needs to send data over the 
>>network, but when it applies the rsync algorithm which is supposed to be 
>>faster than sending all the data over the network. This is very puzzling.
>>
>>For a benchmark, I tried transfering a 5.4 MB mp3 file three different 
>>ways. Here were my results, as reported by 'scp -v' and 'rsync 
>>--progress --stats':
>>
>>    scp: 311000 B/s
>>    rsync (file not there): 309000 B/s
>>    rsync (file already there): 741 B/s
>>
>>When the file is alredy there, rsync reports a speedup of about 70. 
>>(When the file is not already there, the speed up is 1, of course.) I am 
>>running rsync over ssh with pre-generated keys installed in my .ssh 
>>directories.
> 
> 
> rsync under Cygwin is extremly slow and CPU intensive. For example a
> simple script that syncs my dot files from my local NetWare server
> takes 1:10 minutes to run and eats about 60% CPU while on my Gentoo
> box (which has exactly the same hardware) it takes 7 seconds and 2%
> CPU.
> 
> Try disabling checksumming, zipping and transfer the whole file
> ('-W'). Try it without ssh.

I rechecked my test, this time with cygserver enabled. Before I ran it 
without cygserver and without ipc-daemon2. (Forgot if rsync uses now the 
old ipc-daemon2 or the new cygserver or no ipc at all.)
Same (fast) results as expected, for both cases with local files.
-- 
Reini Urban
http://xarch.tu-graz.ac.at/home/rurban/


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