Hey,
#1 Quick question :
What is the difference between using iperf and sending packets and using
filecopy? I get bad speed sending between 12-64K packets with iperf. Only
5Mbit/s on a local network. But if I copy big files everything goes good or if
I add the -w 1MB option. Anyway, I have a case at Microsoft and Vmware and we
are troubleshooting why everything goes slowly in our environment. They asked
me to do a robocopy of 30.000 small files with filesize 12K. And it goes pretty
fast.. so my question is, what is the difference between these two methods in
terms of transferring?
#2 Longer question if you have time to read:
We have the last two months troubleshooted why things go slow in the network
and we have used iperf to see that we have problems from some Server2008 hosts
to other windows servers, but not to Linux server. Its only the send traffic
that goes slow, what we have found out so far:
* If I create a virtual machine and send it to vmware, it will performs
bad 5Mbit/s
* If vmware creates a machine and sends it to us, it will performs good
500Mbit/s
* If I create a virtual machine it performs bad 5Mbit/s
* The virtual machine vmware created had 8K as default TCP window size
and ours has 64K, any comment? Its created from the exact same ISO and the same
procedure
* If we turn up the TCP window Size to 1MB it performs good. 500Mbit/s
* Its only towards other windows machines it performs bad, not towards
a Linux dist.
* It can receive in 500Mbit/s but only send in 5Mbt/s
* Robocopy goes much faster 50Mbit/s if the files are 12K each and I
copy 26.000 files, but I guess small file copies cant go faster
* Regular windows copy from windows t windows goes as fast as Roocopy.
* All machines are clean installs with no firewall or antivirus, just
the latest SP and patches.
It feels like we have tested everything with disabling Offload and all those
tweaks but Im happy to get some new perspectives
Francesco
------------------------------------------------------------------------------
The demand for IT networking professionals continues to grow, and the
demand for specialized networking skills is growing even more rapidly.
Take a complimentary Learning@Cisco Self-Assessment and learn
about Cisco certifications, training, and career opportunities.
http://p.sf.net/sfu/cisco-dev2dev
_______________________________________________
Iperf-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/iperf-users
