High CPU load and slow performance on NT/W2K
Petter Österlund
petos at fyrplus.se
Fri May 17 11:30:02 EST 2002
Hi!
I am experiencing very high CPU load and long update times using
rsync.exe on NT/W2K. The versions I have tested on NT are; 2.4.6, 2.5.1-2
and 2.5.5-2. Cygwin1.dll version 1.3.10. They all show the same kind of
problem.
Is there anything that I might have missed, or is the perfomance not
better than this?
On the other side of the transfer I have used both NT/W2K, Solaris and
Linux.
I have been executing the the rsync command on NT/W2K as well as on the Unix
hosts. The outcome is the same; The NT/W2K machine gets loaded to 100%.
Transfering between the UNIX hosts are no problem. The machines are on a
100Mb/s LAN.
I am doing an update of a 15 MB text file, like this:
(fyrsol2: Solaris2.7, bserv: Win2000)
-----------------
fyrsol2 # touch x.txt ; time rsync-2.5.2 -avv --progress x.txt
bserv::tooltest
rsync: building file list...
rsync: expand file_list to 4000 bytes, did move
rsync: 1 files to consider.
x.txt
15806883 100% 10.27MB/s 0:00:00
total: matches=10081 tag_hits=10081 false_alarms=0 data=0
wrote 40481 bytes read 60542 bytes 8081.84 bytes/sec
total size is 15806883 speedup is 156.47
1.50u 0.39s 0:12.15 15.5%
--------------------
Notice the transfer time is 12 seconds! (The 10.27MB/s reading must be
false).
During this the CPU load of the NT/W2K host is 100% for at least 6-8
seconds.
(The file can be transferred in 1.5 seconds using FTP!)
But now to the realy funny part; If I change the command by adding a -z
option
I get an unexpected performance gain:
----------
fyrsol2 # touch x.txt ; time rsync-2.5.2 -avvz --progress x.txt
bserv::tooltest
rsync: building file list...
rsync: expand file_list to 4000 bytes, did move
rsync: 1 files to consider.
x.txt
15806883 100% 3.67MB/s 0:00:00
total: matches=10081 tag_hits=10081 false_alarms=0 data=0
wrote 158 bytes read 60542 bytes 9338.46 bytes/sec
total size is 15806883 speedup is 260.41
4.23u 0.27s 0:06.03 74.6%
-------------
The update now is done in half the time and the CPU load of the NT/W2K host
is only touching 100% during a very short time at the end of the update.
Any sugestions?
/Petter
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