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funk menera

2007-May-31 16:32 UTC

[Xen-users] low network performance

Hi @list !

This is my first posting so please have patience with
me ;) 

As the titel says, i have some problems with the
network performance.
I''m using Xen3.0.3 with Debian on domO and all over
domUs
Maybe the Hardware is interesting too...
AthlonXP 1700+ on MSI.K7T266Pro2 with 1GB RAM, 3
IDE-HDs without RAID and two Networkdevices with
Realtek chipset: 
NIC1: 1GBit r8169 -> for LAN
NIC2: 100MBit 8139 -> for DSL
on the LAN-device is a D-LINK GBit 8-Port Switch
connected.

Well i experienced the problems while listening to a
mp3 file on a domU using Samba. Or when extracting
sth. from/to a domU form/to my Laptop. Same for a
transport from domU <-> domU 
Basically it feels laggy or not as fast as i''m used to
(as comparison: the same hardware on a debian-srv
withou XEN) and there are hang-ups


So a short test with netio shows me sth. like this:
Laptop -> domO         : 11000 KByte/s for Tx and Rx
domO   -> domU-mainsrv : 
TCP connection established.
Packet size  1k bytes:  1870 KByte/s Tx,  12293
KByte/s Rx.
Packet size  2k bytes:  1659 KByte/s Tx,  13503
KByte/s Rx.
Packet size  4k bytes:  1893 KByte/s Tx,  14072
KByte/s Rx.
Packet size  8k bytes:  1869 KByte/s Tx,  16355
KByte/s Rx.
Packet size 16k bytes:  1810 KByte/s Tx,  14836
KByte/s Rx.
Packet size 32k bytes:  1636 KByte/s Tx,  16829
KByte/s Rx.
Done.

as i go on 
domU -> domU-efw21(Endian Firewall 2.1):
TCP connection established.
Packet size  1k bytes:  6753 KByte/s Tx,  5481 KByte/s
Rx.
Packet size  2k bytes:  6005 KByte/s Tx,  5532 KByte/s
Rx.
Packet size  4k bytes:  6216 KByte/s Tx,  5271 KByte/s
Rx.
Packet size  8k bytes:  5811 KByte/s Tx,  5491 KByte/s
Rx.
Packet size 16k bytes:  6236 KByte/s Tx,  5603 KByte/s
Rx.
Packet size 32k bytes:  5846 KByte/s Tx,  5588 KByte/s
Rx.
Done.

That''s terrific if i compare it with the speed which i
had before ... 28MByte/s ~ 50MB/s

So i read some pages in the mailing list archive and
found sth. about para-virtual drivers which looked
like it could give me more bandwidth.
Anyhow i just got confused ... 
Is para-virtualsiation meanwhile standard for
Linux-domUs ? 
If not where can i get these drivers ? 

Maybe the reason for the low network performance is
somewhere else ? 
Could someone give me good options for the (tcp_rmem
and so) variables in /et/sysctl.conf ? I found a howto
therefore but changing the values didn''t had a
reliable performance enhancement.

A other reason could be that the domO is ''sucking'' in
network traffic ... ?!
Or that i run the system with 100MHz instead of 133MHz
busfrequency ?! But i don''t think so cause i did that
before too.

For any hints, tips or links i will be very thankfully
!


Regards, 
funki 







		
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Petersson, Mats

2007-May-31 16:48 UTC

head link

RE: [Xen-users] low network performance

> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com 
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
> funk menera
> Sent: 31 May 2007 17:32
> To: xen-users@lists.xensource.com
> Subject: [Xen-users] low network performance
> 
> Hi @list !
> 
> This is my first posting so please have patience with
> me ;) 
> 
> As the titel says, i have some problems with the
> network performance.
> I''m using Xen3.0.3 with Debian on domO and all over
> domUs
> Maybe the Hardware is interesting too...
> AthlonXP 1700+ on MSI.K7T266Pro2 with 1GB RAM, 3
> IDE-HDs without RAID and two Networkdevices with
> Realtek chipset: 
> NIC1: 1GBit r8169 -> for LAN
> NIC2: 100MBit 8139 -> for DSL
> on the LAN-device is a D-LINK GBit 8-Port Switch
> connected.
> 
> Well i experienced the problems while listening to a
> mp3 file on a domU using Samba. Or when extracting
> sth. from/to a domU form/to my Laptop. Same for a
> transport from domU <-> domU 
> Basically it feels laggy or not as fast as i''m used to
> (as comparison: the same hardware on a debian-srv
> withou XEN) and there are hang-ups
> 
> 
> So a short test with netio shows me sth. like this:
> Laptop -> domO         : 11000 KByte/s for Tx and Rx
> domO   -> domU-mainsrv : 
> TCP connection established.
> Packet size  1k bytes:  1870 KByte/s Tx,  12293
> KByte/s Rx.
> Packet size  2k bytes:  1659 KByte/s Tx,  13503
> KByte/s Rx.
> Packet size  4k bytes:  1893 KByte/s Tx,  14072
> KByte/s Rx.
> Packet size  8k bytes:  1869 KByte/s Tx,  16355
> KByte/s Rx.
> Packet size 16k bytes:  1810 KByte/s Tx,  14836
> KByte/s Rx.
> Packet size 32k bytes:  1636 KByte/s Tx,  16829
> KByte/s Rx.
> Done.
> 
> as i go on 
> domU -> domU-efw21(Endian Firewall 2.1):
> TCP connection established.
> Packet size  1k bytes:  6753 KByte/s Tx,  5481 KByte/s
> Rx.
> Packet size  2k bytes:  6005 KByte/s Tx,  5532 KByte/s
> Rx.
> Packet size  4k bytes:  6216 KByte/s Tx,  5271 KByte/s
> Rx.
> Packet size  8k bytes:  5811 KByte/s Tx,  5491 KByte/s
> Rx.
> Packet size 16k bytes:  6236 KByte/s Tx,  5603 KByte/s
> Rx.
> Packet size 32k bytes:  5846 KByte/s Tx,  5588 KByte/s
> Rx.
> Done.
> 
> That''s terrific if i compare it with the speed which i
> had before ... 28MByte/s ~ 50MB/s
> 
> So i read some pages in the mailing list archive and
> found sth. about para-virtual drivers which looked
> like it could give me more bandwidth.
> Anyhow i just got confused ... 
> Is para-virtualsiation meanwhile standard for
> Linux-domUs ? 
> If not where can i get these drivers ? 
You are already running para-virtualization, since you''re on an older
Ahtlon XP 1700+, these are a few years away from the current generation
that has the AMD-V feature to allow non-para-virtual OS''s to run on
Xen.

> 
> Maybe the reason for the low network performance is
> somewhere else ? 
Yes, I suspect the real problem here is "CPU congestion". Every packet
you send out goes from the DomU to Dom0, then from Dom0 to the othe DomU
(in the DomU -> DomU case). Since all three of these domains run on the
same processor, the overall latency is much higher than comparing
individual systems. Add to this the fact that the virtual system will
have a higher overhead simply because there is a hypervisor that want''s
to control things too [although this is probably only a small part of
the puzzle]. 

There is nothing you can really do about this, other than getting a new
system that has more CPU(-core)s to allow the processing of packets to
be done more in parallel.
> Could someone give me good options for the (tcp_rmem
> and so) variables in /et/sysctl.conf ? I found a howto
> therefore but changing the values didn''t had a
> reliable performance enhancement.
Probably not worth much, as you''ve found. > 
> A other reason could be that the domO is ''sucking'' in
> network traffic ... ?!
> Or that i run the system with 100MHz instead of 133MHz
> busfrequency ?! But i don''t think so cause i did that
> before too.
No, that will have a small effect in the whole scheme of things. Of
course, Xen and multiple guests will increase the memory bus-traffic, so
higher speed processors/memory controller will help to some extent, but
the 25% increase in bus-frequency will not give 25% performance
improvement here - probably more like 5-10% (or maybe none - depends on
how well the caching works in this case). 

Do you want to have a guess why AMD and Intel are so interested in
virtualization? Nothing better for a processor manufacturer than
something that sucks up a bit more CPU power and makes customers buy new
processors, eh? ;-)

--
Mats> 
> For any hints, tips or links i will be very thankfully
> !
> 
> 
> Regards, 
> funki 
> 
> 
> 
> 
> 
> 
> 
> 		
> ___________________________________________________________ 
> Telefonate ohne weitere Kosten vom PC zum PC: 
> http://messenger.yahoo.de
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
> 
> 
> 


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

Schmidt, Werner (Werner)

2007-Jun-01 07:55 UTC

head link

RE: [Xen-users] low network performance

> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com 
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
> funk menera
> Sent: 31 May 2007 17:32
> To: xen-users@lists.xensource.com
> Subject: [Xen-users] low network performance
> 
> Hi @list !
> 
> This is my first posting so please have patience with
> me ;) 
> 
> As the titel says, i have some problems with the
> network performance.
> I''m using Xen3.0.3 with Debian on domO and all over
> domUs
> Maybe the Hardware is interesting too...
> AthlonXP 1700+ on MSI.K7T266Pro2 with 1GB RAM, 3
> IDE-HDs without RAID and two Networkdevices with
> Realtek chipset: 
> NIC1: 1GBit r8169 -> for LAN
> NIC2: 100MBit 8139 -> for DSL
> on the LAN-device is a D-LINK GBit 8-Port Switch
> connected.
> 
> Well i experienced the problems while listening to a
> mp3 file on a domU using Samba. Or when extracting
> sth. from/to a domU form/to my Laptop. Same for a
> transport from domU <-> domU 
> Basically it feels laggy or not as fast as i''m used to
> (as comparison: the same hardware on a debian-srv
> withou XEN) and there are hang-ups
> 
> 
> So a short test with netio shows me sth. like this:
> Laptop -> domO         : 11000 KByte/s for Tx and Rx
> domO   -> domU-mainsrv : 
> TCP connection established.
> Packet size  1k bytes:  1870 KByte/s Tx,  12293
> KByte/s Rx.
> Packet size  2k bytes:  1659 KByte/s Tx,  13503
> KByte/s Rx.
> Packet size  4k bytes:  1893 KByte/s Tx,  14072
> KByte/s Rx.
> Packet size  8k bytes:  1869 KByte/s Tx,  16355
> KByte/s Rx.
> Packet size 16k bytes:  1810 KByte/s Tx,  14836
> KByte/s Rx.
> Packet size 32k bytes:  1636 KByte/s Tx,  16829
> KByte/s Rx.
> Done.
> 
> as i go on 
> domU -> domU-efw21(Endian Firewall 2.1):
> TCP connection established.
> Packet size  1k bytes:  6753 KByte/s Tx,  5481 KByte/s
> Rx.
> Packet size  2k bytes:  6005 KByte/s Tx,  5532 KByte/s
> Rx.
> Packet size  4k bytes:  6216 KByte/s Tx,  5271 KByte/s
> Rx.
> Packet size  8k bytes:  5811 KByte/s Tx,  5491 KByte/s
> Rx.
> Packet size 16k bytes:  6236 KByte/s Tx,  5603 KByte/s
> Rx.
> Packet size 32k bytes:  5846 KByte/s Tx,  5588 KByte/s
> Rx.
> Done.
> 
> That''s terrific if i compare it with the speed which i
> had before ... 28MByte/s ~ 50MB/s
> 
> So i read some pages in the mailing list archive and
> found sth. about para-virtual drivers which looked
> like it could give me more bandwidth.
> Anyhow i just got confused ... 
> Is para-virtualsiation meanwhile standard for
> Linux-domUs ? 
> If not where can i get these drivers ? 
 
> 
> Maybe the reason for the low network performance is
> somewhere else ?
 

 

Note that i had similar problems in my tests (I tested the domU and dom0
network performance of multiple machines connected via Gigabit lan with
''iperf '')

;

If you use the standard bridge configuration (which I assume is true for
your system), you might try to get a better performance by modifying the
''txqueuelen'' parameter of the vif devices connecting the domUs
to the
dom0 bridge (''ifconfig vifx.y'' will show the value of this
parameter)

You can see with  ''brctl show'' which vifs are involved.

 

In my case, the value was set to ''32''

I got substantially better results of dom0->domU performance (and domU
-> domU performance) by changing this value to 128 ..512:

''ip link set vifx.y txqueuelen <value>'' will do this
change for you

 

Werner

 



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

funk menera

2007-Jun-01 12:43 UTC

head link

RE: [Xen-users] low network performance

"Schmidt, Werner (Werner)" <wernerschmidt@avaya.com> schrieb:   
> -----Original Message-----
  > From: xen-users-bounces@lists.xensource.com 
  > [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
  > funk menera
  > Sent: 31 May 2007 17:32
  > To: xen-users@lists.xensource.com
  > Subject: [Xen-users] low network performance
  > 
  > Hi @list !
  > 
  > This is my first posting so please have patience with
  > me ;) 
  > 
  > As the titel says, i have some problems with the
  > network performance.
  > I''m using Xen3.0.3 with Debian on domO and all over
  > domUs
  > Maybe the Hardware is interesting too...
  > AthlonXP 1700+ on MSI.K7T266Pro2 with 1GB RAM, 3
  > IDE-HDs without RAID and two Networkdevices with
  > Realtek chipset: 
  > NIC1: 1GBit r8169 -> for LAN
  > NIC2: 100MBit 8139 -> for DSL
  > on the LAN-device is a D-LINK GBit 8-Port Switch
  > connected.
  > 
  > Well i experienced the problems while listening to a
  > mp3 file on a domU using Samba. Or when extracting
  > sth. from/to a domU form/to my Laptop. Same for a
  > transport from domU <-> domU 
  > Basically it feels laggy or not as fast as i''m used to
  > (as comparison: the same hardware on a debian-srv
  > withou XEN) and there are hang-ups
  > 
  > 
  > So a short test with netio shows me sth. like this:
  > Laptop -> domO         : 11000 KByte/s for Tx and Rx
  > domO   -> domU-mainsrv : 
  > TCP connection established.
  > Packet size  1k bytes:  1870 KByte/s Tx,  12293
  > KByte/s Rx.
  > Packet size  2k bytes:  1659 KByte/s Tx,  13503
  > KByte/s Rx.
  > Packet size  4k bytes:  1893 KByte/s Tx,  14072
  > KByte/s Rx.
  > Packet size  8k bytes:  1869 KByte/s Tx,  16355
  > KByte/s Rx.
  > Packet size 16k bytes:  1810 KByte/s Tx,  14836
  > KByte/s Rx.
  > Packet size 32k bytes:  1636 KByte/s Tx,  16829
  > KByte/s Rx.
  > Done.
  > 
  > as i go on 
  > domU -> domU-efw21(Endian Firewall 2.1):
  > TCP connection established.
  > Packet size  1k bytes:  6753 KByte/s Tx,  5481 KByte/s
  > Rx.
  > Packet size  2k bytes:  6005 KByte/s Tx,  5532 KByte/s
  > Rx.
  > Packet size  4k bytes:  6216 KByte/s Tx,  5271 KByte/s
  > Rx.
  > Packet size  8k bytes:  5811 KByte/s Tx,  5491 KByte/s
  > Rx.
  > Packet size 16k bytes:  6236 KByte/s Tx,  5603 KByte/s
  > Rx.
  > Packet size 32k bytes:  5846 KByte/s Tx,  5588 KByte/s
  > Rx.
  > Done.
  > 
  > That''s terrific if i compare it with the speed which i
  > had before ... 28MByte/s ~ 50MB/s
  > 
  > So i read some pages in the mailing list archive and
  > found sth. about para-virtual drivers which looked
  > like it could give me more bandwidth.
  > Anyhow i just got confused ... 
  > Is para-virtualsiation meanwhile standard for
  > Linux-domUs ? 
  > If not where can i get these drivers ? 
   
  > 
  > Maybe the reason for the low network performance is
  > somewhere else ?
   
   
  Note that i had similar problems in my tests (I tested the domU and dom0
network performance of multiple machines connected via Gigabit lan with iperf
)
  ;
  If you use the standard bridge configuration (which I assume is true for your
system), you might try to get a better performance by modifying the txqueuelen
parameter of the vif devices connecting the domUs to the dom0 bridge (ifconfig
vifx.y will show the value of this parameter)
  You can see with  brctl show which vifs are involved.
   
  In my case, the value was set to 32
  I got substantially better results of dom0->domU performance (and domU
-> domU performance) by changing this value to 128 ..512:
  ip link set vifx.y txqueuelen <value> will do this change for you
   
  Werner
   
  
  _______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users


Thanks for the reply.
But changing the txqueuelen on all doms to 512 dind''t bring
up some performance enhancements on my system.
Well the value before was a 0 at domO  and 1000 at domUs... what ever that
means.

And i''m using the standard bridge-mode to connect the
doms. But to get sure u may have a look at:
http://www.neobiker.de/wiki/index.php?title=XEN_Netzwerk_f%C3%BCr_Firewall
because i''m using this script for configuring the
network.
But as i understand this script uses bridging ...

Well, do u also have a one-core CPU, so the problem
might be comparible to my or do u use a
dualcore-/quadcore-cpu or dual/quad-system with single
CPUs ? 
This point is interesting for me anyway, because in a
previous mail a Xen-USer told me about that the
performance would be much better on such a system.

So therefore i want to ask all of U@list what kind of
system are u using and how good the performance is? 
So do u use ...
a) a antiquated ;) single-core single CPU system as i
do ? 
b) ''normal'' dual singlecore-cpu System ?
c) 1 dualcore/quadcore cpu ?
d) more then 1 dualcore/quadcore cpu ? ... maybe 4 of
them :O ? ... don''t wanna know how big the overhead
might be in this case :X 

And basically which version would u suggest to run the
best performance? furthermoire i''d like to know if there is a important
performance difference between a AMD or Intel system ?

Allthough i''m not in the situation (as a poor student)
to spend some hundred bucks for a new system :( i''m
interested in that point ... U''ll never know where u
find some money ;) 

So i just wanna know about the performance to solve my
question if the system would run as i was used to or
if there remains some bottlenecks ? 
Basically i don''t need high cpu-power bout a good and
reliable network and harddisk performance !

Reagrds,
fuki

P.S. Any other hint/tips/link for giving my system
better performance is highly desired ! 
 

       
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<br><br><b><i>"Schmidt, Werner (Werner)"
&lt;wernerschmidt@avaya.com&gt;</i></b>
schrieb:<blockquote class="replbq" style="border-left: 2px
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class="Section1">  <div class="MsoNormal"><font
face="Arial" size="2"><span style="font-size:
10pt; font-family: Arial;" lang="EN-GB">&gt; -----Original
Message-----<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; From:
xen-users-bounces@lists.xensource.com
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;">&gt; funk
menera<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;">&gt; Sent: 31 May 2007
17:32<o:p></o:p></span></font></div>
 <div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; To:
xen-users@lists.xensource.com<o:p></o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Subject: [Xen-users] low network
performance<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Hi @list
!<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; This is my
 first posting so please have patience
with<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; me ;)
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; As the titel says, i have some
problems with the<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; network
performance.<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; I''m using Xen3.0.3 with
Debian on domO and all
over<o:p></o:p></span></font></div>  <div
 class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
domUs<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Maybe the Hardware is
interesting too...<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; AthlonXP 1700+ on MSI.K7T266Pro2
with 1GB RAM, 3<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; IDE-HDs without RAID and two
Networkdevices with<o:p></o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;">&gt; Realtek chipset:
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt;
 font-family: Arial;">&gt; NIC1: 1GBit r8169 -&gt; for
LAN<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; NIC2: 100MBit 8139 -&gt; for
DSL<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; on the LAN-device is a D-LINK
GBit 8-Port Switch<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
connected.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Well i experienced the problems
while listening to
 a<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; mp3 file on a domU using Samba.
Or when extracting<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; sth. from/to a domU form/to my
Laptop. Same for a<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; transport from domU
&lt;-&gt; domU
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Basically it feels laggy or not
as fast as i''m used
to<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; (as comparison: the same
hardware
 on a debian-srv<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; withou XEN) and there are
hang-ups<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; So a short test with netio shows
me sth. like this:<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Laptop -&gt;
domO&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
: 11000 KByte/s for Tx and
 Rx<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; domO&nbsp;&nbsp;
-&gt; domU-mainsrv :
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; TCP connection
established.<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 1k
bytes:&nbsp; 1870 KByte/s Tx,&nbsp;
12293<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 2k
bytes:&nbsp; 1659 KByte/s Tx,&nbsp;
 13503<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 4k
bytes:&nbsp; 1893 KByte/s Tx,&nbsp;
14072<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 8k
bytes:&nbsp; 1869 KByte/s Tx,&nbsp;
16355<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
 class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size 16k bytes:&nbsp;
1810 KByte/s Tx,&nbsp;
14836<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size 32k bytes:&nbsp;
1636 KByte/s Tx,&nbsp;
16829<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; KByte/s
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Done.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt;
 font-family: Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; as i go on
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; domU -&gt; domU-efw21(Endian
Firewall 2.1):<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; TCP connection
established.<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 1k
bytes:&nbsp; 6753 KByte/s Tx,&nbsp; 5481
KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
 Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 2k
bytes:&nbsp; 6005 KByte/s Tx,&nbsp; 5532
KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 4k
bytes:&nbsp; 6216 KByte/s Tx,&nbsp; 5271
KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size&nbsp; 8k
bytes:&nbsp; 5811 KByte/s Tx,&nbsp; 5491
 KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size 16k bytes:&nbsp;
6236 KByte/s Tx,&nbsp; 5603
KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Packet size 32k bytes:&nbsp;
5846 KByte/s Tx,&nbsp; 5588
KByte/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Rx.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
 size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
Done.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; That''s terrific if i
compare it with the speed which
i<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; had before ... 28MByte/s ~
50MB/s<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; So i read some pages in the
mailing list archive
 and<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; found sth. about para-virtual
drivers which
looked<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; like it could give me more
bandwidth.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Anyhow i just got confused ...
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Is para-virtualsiation meanwhile
standard for<o:p></o:p></span></font></div> 
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Linux-domUs ?
<o:p></o:p></span></font></div>  <div
 class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; If not where can i get these
drivers ? <o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"
lang="EN-GB"><o:p>&nbsp;</o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt;
<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">&gt; Maybe the reason for the low
network performance
is<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;">&gt; somewhere else
?<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
 Arial;"><o:p>&nbsp;</o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"><o:p>&nbsp;</o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">Note that i had similar problems in my
tests (I tested the domU and dom0 network performance of multiple machines
connected via Gigabit lan with iperf
)<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"
lang="EN-GB">;<o:p></o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">If you use the standard bridge
configuration (which I assume is true for your system), you might try to get a
better performance by modifying the txqueuelen parameter of the vif devices
connecting the domUs to the dom0 bridge
 (ifconfig vifx.y will show the value of this
parameter)<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">You can see with&nbsp; brctl show
which vifs are
involved.<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"
lang="EN-GB"><o:p>&nbsp;</o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">In my case, the value was set to
32<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;" lang="EN-GB">I got substantially better results of
dom0-&gt;domU performance (and domU -&gt; domU performance) by changing
this value to 128
..512:<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span
 style="font-size: 10pt; font-family: Arial;"
lang="EN-GB">ip link set vifx.y txqueuelen &lt;value&gt;
will do this change for
you<o:p></o:p></span></font></div>  <div
class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"
lang="EN-GB"><o:p>&nbsp;</o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;">Werner<o:p></o:p></span></font></div>
<div class="MsoNormal"><font face="Arial"
size="2"><span style="font-size: 10pt; font-family:
Arial;"><o:p>&nbsp;</o:p></span></font></div>
</div>  _______________________________________________<br>Xen-users
mailing
list<br>Xen-users@lists.xensource.com<br>http://lists.xensource.com/xen-users<br></blockquote><br><pre><tt><tt><tt><tt>Thanks
for the reply.<br>But changing the txqueuelen on all doms to 512
dind''t bring<br>up some performance enhancements on my
system.<br>Well the value before was a 0 at domO  and 1000 at
 domUs... what ever that<br>means.<br><br>And i''m
using the standard bridge-mode to connect the<br>doms. But to get sure u
may have a look at:<br><a
href="http://www.neobiker.de/wiki/index.php?title=XEN_Netzwerk_f%C3%BCr_Firewall"
target="_blank">http://www.neobiker.de/wiki/index.php?title=XEN_Netzwerk_f%C3%BCr_Firewall</a><br>because
i''m using this script for configuring
the<br>network.<br>But as i understand this script uses bridging
...<br><br>Well, do u also have a one-core CPU, so the
problem<br>might be comparible to my or do u use
a<br>dualcore-/quadcore-cpu or dual/quad-system with single<br>CPUs
? <br>This point is interesting for me anyway, because in
a<br>previous mail a Xen-USer told me about that the<br>performance
would be much better on such a system.<br><br>So therefore i want to
ask all of U@list what kind of<br>system are u using and how good the
performance is? <br>So do u use ...<br>a) a antiquated ;)
single-core single CPU system as i<br>do ? <br>b)
 ''normal'' dual singlecore-cpu System ?<br>c) 1
dualcore/quadcore cpu ?<br>d) more then 1 dualcore/quadcore cpu ? ...
maybe 4 of<br>them :O ? ... don''t wanna know how big the
overhead<br>might be in this case :X <br><br>And basically
which version would u suggest to run the<br>best performance? furthermoire
i''d like to know if there is a important performance difference between
a AMD or Intel system ?<br><br>Allthough i''m not in the
situation (as a poor student)<br>to spend some hundred bucks for a new
system :( i''m<br>interested in that point ... U''ll never
know where u<br>find some money ;) <br><br>So i just wanna
know about the performance to solve my<br>question if the system would run
as i was used to or<br>if there remains some bottlenecks ?
<br>Basically i don''t need high cpu-power bout a good
and<br>reliable network and harddisk performance
!<br><br>Reagrds,<br>fuki<br><br>P.S. Any other
hint/tips/link for giving my system<br>better performance is highly
desired !
 </tt></tt></tt></tt></pre>
<br><p>&#32;



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Petersson, Mats

2007-Jun-01 13:19 UTC

head link

RE: [Xen-users] low network performance

> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com 
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
> funk menera
> Sent: 01 June 2007 13:43
> To: Schmidt, Werner (Werner); xen-users@lists.xensource.com
> Subject: RE: [Xen-users] low network performance
> 
> 
> 
> "Schmidt, Werner (Werner)" <wernerschmidt@avaya.com>
schrieb:
> 
> 	> -----Original Message-----
> 	> From: xen-users-bounces@lists.xensource.com 
> 	> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of 
> 	> funk menera
> 	> Sent: 31 May 2007 17:32
> 	> To: xen-users@lists.xensource.com
> 	> Subject: [Xen-users] low network performance
> 	> 
> 	> Hi @list !
> 	> 
> 	> This is my first posting so please have patience with
> 	> me ;) 
> 	> 
> 	> As the titel says, i have some problems with the
> 	> network performance.
> 	> I''m using Xen3.0.3 with Debian on domO and all over
> 	> domUs
> 	> Maybe the Hardware is interesting too...
> 	> AthlonXP 1700+ on MSI.K7T266Pro2 with 1GB RAM, 3
> 	> IDE-HDs without RAID and two Networkdevices with
> 	> Realtek chipset: 
> 	> NIC1: 1GBit r8169 -> for LAN
> 	> NIC2: 100MBit 8139 -> for DSL
> 	> on the LAN-device is a D-LINK GBit 8-Port Switch
> 	> connected.
> 	> 
> 	> Well i experienced the problems while listening to a
> 	> mp3 file on a domU using Samba. Or when extracting
> 	> sth. from/to a domU form/to my Laptop. Same for a
> 	> transport from domU <-> domU 
> 	> Basically it feels laggy or not as fast as i''m used to
> 	> (as comparison: the same hardware on a debian-srv
> 	> withou XEN) and there are hang-ups
> 	> 
> 	> 
> 	> So a short test with netio shows me sth. like this:
> 	> Laptop -> domO         : 11000 KByte/s for Tx and Rx
> 	> domO   -> domU-mainsrv : 
> 	> TCP connection established.
> 	> Packet size  1k bytes:  1870 KByte/s Tx,  12293
> 	> KByte/s Rx.
> 	> Packet size  2k bytes:  1659 KByte/s Tx,  13503
> 	> KByte/s Rx.
> 	> Packet size  4k bytes:  1893 KByte/s Tx,  14072
> 	> KByte/s Rx.
> 	> Packet size  8k bytes:  1869 KByte/s Tx,  16355
> 	> KByte/s Rx.
> 	> Packet size 16k bytes:  1810 KByte/s Tx,  14836
> 	> KByte/s Rx.
> 	> Packet size 32k bytes:  1636 KByte/s Tx,  16829
> 	> KByte/s Rx.
> 	> Done.
> 	> 
> 	> as i go on 
> 	> domU -> domU-efw21(Endian Firewall 2.1):
> 	> TCP connection established.
> 	> Packet size  1k bytes:  6753 KByte/s Tx,  5481 KByte/s
> 	> Rx.
> 	> Packet size  2k bytes:  6005 KByte/s Tx,  5532 KByte/s
> 	> Rx.
> 	> Packet size  4k bytes:  6216 KByte/s Tx,  5271 KByte/s
> 	> Rx.
> 	> Packet size  8k bytes:  5811 KByte/s Tx,  5491 KByte/s
> 	> Rx.
> 	> Packet size 16k bytes:  6236 KByte/s Tx,  5603 KByte/s
> 	> Rx.
> 	> Packet size 32k bytes:  5846 KByte/s Tx,  5588 KByte/s
> 	> Rx.
> 	> Done.
> 	> 
> 	> That''s terrific if i compare it with the speed which i
> 	> had before ... 28MByte/s ~ 50MB/s
> 	> 
> 	> So i read some pages in the mailing list archive and
> 	> found sth. about para-virtual drivers which looked
> 	> like it could give me more bandwidth.
> 	> Anyhow i just got confused ... 
> 	> Is para-virtualsiation meanwhile standard for
> 	> Linux-domUs ? 
> 	> If not where can i get these drivers ? 
> 	 
> 	> 
> 	> Maybe the reason for the low network performance is
> 	> somewhere else ?
> 	 
> 	 
> 	Note that i had similar problems in my tests (I tested 
> the domU and dom0 network performance of multiple machines 
> connected via Gigabit lan with ''iperf '')
> 	;
> 	If you use the standard bridge configuration (which I 
> assume is true for your system), you might try to get a 
> better performance by modifying the ''txqueuelen''
parameter of
> the vif devices connecting the domUs to the dom0 bridge 
> (''ifconfig vifx.y'' will show the value of this parameter)
> 	You can see with  ''brctl show'' which vifs are involved.
> 	 
> 	In my case, the value was set to ''32''
> 	I got substantially better results of dom0->domU 
> performance (and domU -> domU performance) by changing this 
> value to 128 ..512:
> 	''ip link set vifx.y txqueuelen <value>'' will do
this
> change for you
> 	 
> 	Werner
> 	 
> 	_______________________________________________
> 	Xen-users mailing list
> 	Xen-users@lists.xensource.com
> 	http://lists.xensource.com/xen-users
> 	
> 
> 
> Thanks for the reply.
> But changing the txqueuelen on all doms to 512 dind''t bring
> up some performance enhancements on my system.
> Well the value before was a 0 at domO  and 1000 at
>  domUs... what ever that
> means.
> 
> And i''m using the standard bridge-mode to connect the
> doms. But to get sure u may have a look at:
> http://www.neobiker.de/wiki/index.php?title=XEN_Netzwerk_f%C3%
> BCr_Firewall
> because i''m using this script for configuring the
> network.
> But as i understand this script uses bridging ...
> 
> Well, do u also have a one-core CPU, so the problem
> might be comparible to my or do u use a
> dualcore-/quadcore-cpu or dual/quad-system with single
> CPUs ? 
> This point is interesting for me anyway, because in a
> previous mail a Xen-USer told me about that the
> performance would be much better on such a system.
> 
> So therefore i want to ask all of U@list what kind of
> system are u using and how good the performance is? 
> So do u use ...
> a) a antiquated ;) single-core single CPU system as i
> do ? 
> b)
>  ''normal'' dual singlecore-cpu System ?
> c) 1 dualcore/quadcore cpu ?
> d) more then 1 dualcore/quadcore cpu ? ... maybe 4 of
> them :O ? ... don''t wanna know how big the overhead
> might be in this case :X 
> 
> And basically which version would u suggest to run the
> best performance? furthermoire i''d like to know if there is a 
> important performance difference between a AMD or Intel system ?
> 
> Allthough i''m not in the situation (as a poor student)
> to spend some hundred bucks for a new system :( i''m
> interested in that point ... U''ll never know where u
> find some money ;) 
> 
> So i just wanna know about the performance to solve my
> question if the system would run as i was used to or
> if there remains some bottlenecks ? 
> Basically i don''t need high cpu-power bout a good and
> reliable network and harddisk performance !
> 
> Reagrds,
> fuki
> 
> P.S. Any other hint/tips/link for giving my system
> better performance is highly desired !
>  
> 
> 
> ________________________________
> 
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> 


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Petersson, Mats

2007-Jun-01 13:37 UTC

head link

RE: [Xen-users] low network performance

Sorry about the previous message - hit send before I should have.  
> 
> Thanks for the reply.
> But changing the txqueuelen on all doms to 512 dind''t bring
> up some performance enhancements on my system.
> Well the value before was a 0 at domO  and 1000 at
>  domUs... what ever that
> means.
> 
> And i''m using the standard bridge-mode to connect the
> doms. But to get sure u may have a look at:
> http://www.neobiker.de/wiki/index.php?title=XEN_Netzwerk_f%C3%
> BCr_Firewall
> because i''m using this script for configuring the
> network.
> But as i understand this script uses bridging ...
> 
> Well, do u also have a one-core CPU, so the problem
> might be comparible to my or do u use a
> dualcore-/quadcore-cpu or dual/quad-system with single
> CPUs ? 
> This point is interesting for me anyway, because in a
> previous mail a Xen-USer told me about that the
> performance would be much better on such a system.
That was me, and the reason I believe this will help is simply that
there are three "processes" running when you do DomU-DomU network
traffic, and none of the traffic actually hit a real network device ever
- it''s all about software that copies data from one place to another
(and the relevant cross-domain interactions to wake the next domain,
etc). 
> 
> So therefore i want to ask all of U@list what kind of
> system are u using and how good the performance is? 
> So do u use ...
> a) a antiquated ;) single-core single CPU system as i
> do ? 
> b)
>  ''normal'' dual singlecore-cpu System ?
> c) 1 dualcore/quadcore cpu ?
> d) more then 1 dualcore/quadcore cpu ? ... maybe 4 of
> them :O ? ... don''t wanna know how big the overhead
> might be in this case :X 
For optimal system performance, you want at least Dom0 to have it''s own
CPU-core (or at the very very least it''s own hyperthread, so at least
the registers don''t need reloading). 

Having at least two cores will help quite a bit - and that''s what
I''m
using for my development work. [But I don''t sit and measure network
performance daily - or at all, really. As long as I can connect my
machine to the corporate network, I''m happy - and for many purposes,
the
corporate network is more of an issue than the data-transfer between my
local machines anyways]. > 
> And basically which version would u suggest to run the
> best performance? furthermoire i''d like to know if there is a 
> important performance difference between a AMD or Intel system ?
There isn''t a BIG difference for otherwise comparable CPU''s
(e.g
comparing dual core of similar[1] speeds gives similar results,
comparing a dual core to a quad core isn''t really fair!

One thing to consider is that running Xen (or any other virtualization
platform) will use more memory, and memory bandwidth becomes a more
important factor than in this case than under a single OS. 

[1] Note that we shouldn''t really use MHz as a "speed"
comaparator, as
that is only useful within a particular processor model - different
models have different "performance per MHz". Unfortunately, there is
no
unbiased other measurement - so the only real solution is to look at
(independent) benchmarks that are doing the same or similar task(s) as
you want to do on your machine. 
> 
> Allthough i''m not in the situation (as a poor student)
> to spend some hundred bucks for a new system :( i''m
> interested in that point ... U''ll never know where u
> find some money ;) 
I would personally recommend a low-end AM2 Dual Core processor and
related motherboard/memory. [Somehting like a 3800+ AM2 processor isn''t
very expensive]. A quick google found someone selling a Motherboard +
processor + 2GB DDR2 memory for just under $300 - this may not be the
best price available, but it''s a guide to the pricing of this [and you
being in Germany will of course have to find a better place than the US
to buy it, as US prices may be all well and good, but shipping will most
likely kill any benefit of lower US prices... ]

The AM2 processors (except for Sempron models) also let you use the HVM
(full virtualization) mode that will allow you to run Windows, OS/2 or
any other OS that hasn''t been "Xenified" yet. 

--
Mats



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Xen users - May 2007 - low network performance

[Xen-users] low network performance

RE: [Xen-users] low network performance

RE: [Xen-users] low network performance

RE: [Xen-users] low network performance

RE: [Xen-users] low network performance

RE: [Xen-users] low network performance