From: Gordon Messmer <gordon.messmer@gmail.com>
To: kvm@vger.kernel.org
Subject: Slow TCP performance from Win2k8R2 guests under Linux KVM
Date: Mon, 15 Jul 2013 15:10:33 -0700 [thread overview]
Message-ID: <51E47359.4070203@gmail.com> (raw)
Would anyone be so kind as to test the performance of TCP streams on
Windows 2k8R2 guests of KVM virt servers?
Red Hat's virtio-win-1.6.3 package was published to address a problem
described as "low performance" on Win2k8 guests. Actual performance was
not recorded in the bug report.
On my KVM servers, Windows 2k8R2 guests are able to send data at less
than 4Mbps. I test this by using netcat on Windows and piping a file to
its input. The receiving end of the transfer is an un-virtualized
CentOS system. Transfer rate is measured by selecting the stream in
iptraf while it is active.
UDP transfers, such as by CIFS, will send data at around 400Mbps.
TCP transfers from Windows 2012 or Windows 8 are not similarly affected.
The same driver for Win2k8 was published by Red Hat in virtio-win 1.6.3,
1.6.4, and 1.6.5.
Does anyone see TCP transfer rates from Win2k8R2 that don't look
ridiculously slow?
https://bugzilla.redhat.com/show_bug.cgi?id=859882
http://rhn.redhat.com/errata/RHBA-2013-0441.html
http://joncraton.org/blog/46/netcat-for-windows
next reply other threads:[~2013-07-15 22:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-15 22:10 Gordon Messmer [this message]
2013-07-21 10:32 ` Slow TCP performance from Win2k8R2 guests under Linux KVM Yan Vugenfirer
2013-07-23 5:24 ` Gordon Messmer
2013-07-23 13:46 ` Yan Vugenfirer
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