Re: [Xen-users] nic poor performance after upgrade to xen 3.2

[tmac <tmacmd@xxxxxxxxx>]

place "sysctl -p" as the first line in the /etc/init.d/netfs right after the first stanza of comments.

try these changes to the /etc/sysctl.conf file on the Guests
(for the host, the last line, sunrpc, is not available, so remove it)

net.core.netdev_max_backlog = 30000
net.core.rmem_default = 256960

net.core.rmem_max = 16777216

net.core.wmem_default = 256960

net.core.wmem_max = 16777216

net.core.rmem_default = 65536
net.core.wmem_default = 65536
net.core.rmem_max = 8388608
net.core.wmem_max = 8388608
net.ipv4.tcp_rmem = 4096 87380 4194304
net.ipv4.tcp_wmem = 4096 16384 4194304
net.ipv4.tcp_mem = 4096 4096 4096
sunrpc.tcp_slot_table_entries = 128

On Feb 6, 2008 11:27 AM, Riccardo Veraldi <Riccardo.Veraldi@xxxxxxxxxxxx> wrote:

I think you use netfront to achieve such performances on domU
so you have to recompile in unmodified_drivers/linux-2.6  from Xen
sources under your domU
and load the kernel modules at boot time

xen-vnif.ko xen-platform-pci.ko xen-vbd.ko xen-balloon.ko

you must alias eth0 xen-vnif in modprobe.conf and of couse use netfront
instead of ioemu
in the vif part of your guest config file. But I think this step is
already done on your guest
otherwise you cannot achieve such a speed with vif type set to ioemu.

Riccardo




Omar Schiaratura ha scritto:

> Hi,
> I'm doing some test on a network 10 gb nics and xen
> with version 3.1 i'm measuring 2.5 gb/sec from domU to an external physical machine with iperf.
> switching to 3.2 has reduced the measured performance to 40-50 Mb/sec.
>
> did anything change in the network interface?
>
> can someone help me?
>
> thanks
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
>


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

-- 
--tmac

RedHat Certified Engineer #804006984323821 (RHEL4)
RedHat Certified Engineer #805007643429572 (RHEL5)

Principal Consultant, RABA Technologies

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users