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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-users] Impressive Performance Problems with Small-Files /Small Blocksizes
Hi Andreas, You really should run I/O tests that run outside of host memory so you can see the performance hit at the disk level. Otherwise you are just testing RAM. I would like to see your results, but I am also interested in seeing the disk performance, not just testing of the RAM. I am collecting my results here: http://github.com/deshantm/Rapid-Recovery-Desktop-Testing/tree/master/results My guest systems have 1G allocated to them. The host system has 4 GB. Desktop class system, Intel Core 2 duo 2.4 GHz. So far only KVM, but Xen is planned for future work. Thanks, Todd On Mon, Aug 9, 2010 at 5:09 AM, Balg, Andreas <a.balg@xxxxxxxx> wrote: > Hello Todd, > > I've allocated 2GB of memory to the guests - The host-system has 16GB of RAM > and I run 7 VMs only - so all happens within the boundaries of physical RAM. > > I could offer you the raw data as well - I could send you an excel Sheet with > all of the Graphs and data used so far. Would that be useful to you? Of course > I'd be interested in your results as well. > > Thanks, > Andreas > > > -- > ----------------------------------------------------------------------------- > XiNCS GmbH MwST-Nr: 695 740 > Schmidshaus 118 HR-Nr: CH-300.4.015.621-9 > CH-9064 Hundwil AR > > Webseite: http://www.xincs.eu > AGB: http://www.xincs.eu/agb.html > Tel. +41 (0)31 526 50 95 > ----------------------------------------------------------------------------- > > > ----- Originalnachricht ----- > Von: Todd Deshane <deshantm@xxxxxxxxx> > Gesendet: Son, 8.8.2010 03:17 > An: "Balg, Andreas" <a.balg@xxxxxxxx> > Betreff: Re: [Xen-users] Impressive Performance Problems with Small-Files > /Small Blocksizes > > Hi, > > How much memory is allocated to the guests? The reason I ask is that > are these runs all or most in memory? > > Do you have raw data that I could look at? > > I am doing some benchmarking of my own and trying to figure out some > strange KVM data. > > Thanks, > Todd > > On Fri, Aug 6, 2010 at 8:06 AM, Balg, Andreas <a.balg@xxxxxxxx> wrote: >> >> hello everybody, >> >> during some extensive benchmarking for an evaluation we found some issues >> with >> i/o-performance and also memory bandwidth of Xen 3.4.2 (using XCP-0.5) >> running >> on a quite up-to-date and performant Dell-R610 Server (2 x Xeon E5620, 16G >> RAM, >> 4 x SATA 15K HDD's - RAID 5): >> >> - Especially for small block sizes (below 32k) the I/O is very poor. >> >> to give some figures: The same Benchmark >> "time iozone -az -i0 -i1 -i2 -i8 -Rb results.xls" >> >> Runs around 3 Minutes on the bare Hardware, around 30 Minutes in a KVM-VM >> and more than 1 hour(!) in a xen VM - See attached graphs and focus on the >> front of the diagram (red and blue "foot" of the xen graph) >> >> What I'd like to know is, if this is be a glitch in a device driver, an >> error in our configuration or might be eliminated in any other way using a >> workaround or other version. >> >> Or is this a proble of the differences in Design or just nobody noticed it >> so far and it should be lokked at by the developers. Without these two >> significant problems Xen would outperform kvm in almost any possible manner >> .... >> >> >> Best regards >> Andreas >> >> >> >> -- >> ----------------------------------------------------------------------------- >> XiNCS GmbH MwST-Nr: 695 740 >> Schmidshaus 118 HR-Nr: CH-300.4.015.621-9 >> CH-9064 Hundwil AR >> >> Webseite: http://www.xincs.eu >> AGB: http://www.xincs.eu/agb.html >> Tel. +41 (0)31 526 50 95 >> ----------------------------------------------------------------------------- >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@xxxxxxxxxxxxxxxxxxx >> http://lists.xensource.com/xen-users >> > > > > -- > Todd Deshane > http://todddeshane.net > http://runningxen.com > -- Todd Deshane http://todddeshane.net http://runningxen.com _______________________________________________ Xen-users mailing list Xen-users@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-users
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