From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Tongiani Subject: Re: Question about VirtIO on Xen - Disk performance issues Date: Tue, 5 Jan 2016 15:44:43 +0100 Message-ID: <568BD6DB.8070200@sinte.net> References: <56701113.1080107@sinte.net> <568BA0B8.2030807@sinte.net> <568BB56A.9090001@sinte.net> <568BCAB7.7010502@sinte.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------020303070908090404020103" Return-path: Received: from mail6.bemta4.messagelabs.com ([85.158.143.247]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1aGSqw-0001bK-1X for xen-devel@lists.xenproject.org; Tue, 05 Jan 2016 14:44:50 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini Cc: xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org This is a multi-part message in MIME format. --------------020303070908090404020103 Content-Type: multipart/alternative; boundary="------------080901020107060303090507" --------------080901020107060303090507 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Hi, Thanks for the hints , I did experiment with the changes you suggested and now we were able to achieve the following result : the performance of the domU is 50 % of the dom0 . Is it possible to improve these numbers more ? Also , do you have any advice on where to find extensive documentation on how to use Xen ? Thank you Luca Il 05/01/2016 15:05, Stefano Stabellini ha scritto: > There are a few issues in the config files. In conf_DomU_WindowsHVM: > > - device_model is set to /usr/lib64/xen/bin/qemu-dm, which is the old > qemu-xen-traditional device model, known to have worse disk > performance. Just delete this line to use the newer QEMU based tree. > - disk is set to [ '/dev/vg0/winvirtio,raw,xvda1,rw' ], but you cannot > expose only a partition of a disk to a Windows HVM domain. The correct > disk line would be: disk = [ '/dev/vg0/winvirtio,raw,hda,rw' ] > > In conf_DomU_Xen: > > - you are missing builder="hvm", which means you are using a PV guest > rather than an HVM guest. PV guests tends to be slower on new > hardware. > > What version of Xen are you using? > > > On Tue, 5 Jan 2016, Luca Tongiani wrote: >> Sorry but I sent these logs because I have no longer available the Virtualizer of Windows DomU . >> In any case the problem of the performance of disks is present both in the case of Linux machines PV and Windows >> machines HVM . >> I attach the complete log of the server and the conf of my HVM Windows Machine. >> >> Thanks again >> >> >> Il 05/01/2016 13:42, Stefano Stabellini ha scritto: >> >> The xenstore-ls output is not complete. Could you please send it again? >> >> I noticed from the DomU config file that it is not a Windows VM, as >> previously discussed, but a Linux VM. That is OK, but of course in that >> case you won't be able to use the Windows PV drivers which I linked. >> Linux has its own set of drivers. Did you enable the Xen PV frontends in >> the Linux kernel you use (/var/xen/boot/vmlinuz-4.0.5-gentoo_bmsbackup)? >> Did you compile them a built-in or as modules? >> >> On Tue, 5 Jan 2016, Luca Tongiani wrote: >> >> Hi, >> thanks in advance for your reply :) >> >> >> I have attached the following email configuration DomU and the output you have requested . >> Performance disk are all my machines the most serious problem , even if they are used powerful hardware . >> Differences in Disk writing in DomU are 1/3 of those of the Dom0 . >> >> >> Thank you in advance Luca >> >> >> >> >> >> >> >> Il 05/01/2016 12:09, Stefano Stabellini ha scritto: >> >> Could you please post your VM config file and the output of >> xenstore-ls once the VM has completed the boot sequence? >> >> On Tue, 5 Jan 2016, Luca Tongiani wrote: >> >> Hi Stefano, >> im writing to you because im having issue with I/O disk in my DomU With Xen (Gentoo based system). >> >> I tried to use the driver that you provided for the PV . >> But the results are still not good , there is no way to support the use of Xen VirtIO disk ? Many thanks in >> advance >> >> Luca >> >> Il 12/16/15 12:31, Stefano Stabellini ha scritto: >> >> Hello Luca, >> >> the recommended way to increase disk performance would be to use Xen PV >> disks. You just need to install the Windows PV drivers: >> >> http://www.xenproject.org/developers/teams/windows-pv-drivers.html >> >> But using VirtIO disk should also increase performance, even though >> most probably not as much. >> >> Cheers, >> >> Stefano >> >> On Tue, 15 Dec 2015, Luca Tongiani wrote: >> >> Hi to all, >> I'm writing you this mail for asking some advice about a great problem i'm havin in running a Windows VM >> (HVM) onto a Xen (Gentoo based) Hypevisor. >> >> I need to achieve maximum performance from this VM because of intense SQL tasks running in it. >> >> I've seen good improvement in IO on disk using VirtIO on a Windows VM onto a QEMU (QNAP) hypervisor, and i'm >> tryin to use this feature also on my Xen HV. >> Is VirtIO disk a good way to improve performance? >> >> Thx in advance and hope to keep in touch >> -- >> >> Luca Tongiani >> >> Sinte srl >> Soluzioni Informatiche e Telematiche >> via Monte Grappa 4/B >> 20900 Monza (MB) >> >> Cel (+39) 339 745 49 21 >> Tel (+39) 039 200 59 60 >> Fax (+39) 039 200 69 42 >> Web www.sinte.net >> >> >> >> >> -- >> >> Luca Tongiani >> >> Sinte srl >> Soluzioni Informatiche e Telematiche >> via Monte Grappa 4/B >> 20900 Monza (MB) >> >> Tel (+39) 039 200 59 60 >> Fax (+39) 039 200 69 42 >> Web www.sinte.net >> >> >> >> >> -- >> >> Luca Tongiani >> >> Sinte srl >> Soluzioni Informatiche e Telematiche >> via Monte Grappa 4/B >> 20900 Monza (MB) >> >> Tel (+39) 039 200 59 60 >> Fax (+39) 039 200 69 42 >> Web www.sinte.net >> >> >> >> >> -- >> >> Luca Tongiani >> >> Sinte srl >> Soluzioni Informatiche e Telematiche >> via Monte Grappa 4/B >> 20900 Monza (MB) >> >> Tel (+39) 039 200 59 60 >> Fax (+39) 039 200 69 42 >> Web www.sinte.net >> >> >> -- *Luca Tongiani* *Sinte* srl Soluzioni Informatiche e Telematiche via Monte Grappa 4/B 20900 Monza (MB) *Tel* (+39) 039 200 59 60 *Fax* (+39) 039 200 69 42 *Web* www.sinte.net --------------080901020107060303090507 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 7bit Hi,
Thanks for the hints , I did experiment with the changes you suggested and now we were able to achieve the following result : the performance of the domU is 50 % of the dom0 .

Is it possible to improve these numbers more ?

Also , do you have any advice on where to find extensive documentation on how to use Xen ?

Thank you

Luca

Il 05/01/2016 15:05, Stefano Stabellini ha scritto:
There are a few issues in the config files. In conf_DomU_WindowsHVM:

- device_model is set to /usr/lib64/xen/bin/qemu-dm, which is the old
  qemu-xen-traditional device model, known to have worse disk
  performance. Just delete this line to use the newer QEMU based tree.
- disk is set to [ '/dev/vg0/winvirtio,raw,xvda1,rw' ], but you cannot
  expose only a partition of a disk to a Windows HVM domain. The correct
  disk line would be: disk = [ '/dev/vg0/winvirtio,raw,hda,rw' ]

In conf_DomU_Xen:

- you are missing builder="hvm", which means you are using a PV guest
  rather than an HVM guest. PV guests tends to be slower on new
  hardware.

What version of Xen are you using?


On Tue, 5 Jan 2016, Luca Tongiani wrote:

Sorry but I sent these logs because I have no longer available the Virtualizer of Windows DomU .
In any case the problem of the performance of disks is present both in the case of Linux machines PV and Windows
machines HVM .
I attach the complete log of the server and the conf of my HVM Windows Machine.

Thanks again


Il 05/01/2016 13:42, Stefano Stabellini ha scritto:

The xenstore-ls output is not complete. Could you please send it again?

I noticed from the DomU config file that it is not a Windows VM, as
previously discussed, but a Linux VM. That is OK, but of course in that
case you won't be able to use the Windows PV drivers which I linked.
Linux has its own set of drivers. Did you enable the Xen PV frontends in
the Linux kernel you use (/var/xen/boot/vmlinuz-4.0.5-gentoo_bmsbackup)?
Did you compile them a built-in or as modules?

On Tue, 5 Jan 2016, Luca Tongiani wrote:

Hi,
thanks in advance for your reply :)


I have attached the following email configuration DomU and the output you have requested .
Performance disk are all my machines the most serious problem , even if they are used powerful hardware .
Differences in Disk writing in DomU are 1/3 of those of the Dom0 .


Thank you in advance Luca







Il 05/01/2016 12:09, Stefano Stabellini ha scritto:

Could you please post your VM config file and the output of
xenstore-ls once the VM has completed the boot sequence?

On Tue, 5 Jan 2016, Luca Tongiani wrote:

Hi Stefano,
im writing to you because im having issue with I/O disk in my DomU With Xen (Gentoo based system).

I tried to use the driver that you provided for the PV .
But the results are still not good , there is no way to support the use of Xen VirtIO disk ? Many thanks in
advance

Luca

Il 12/16/15 12:31, Stefano Stabellini ha scritto:

Hello Luca,

the recommended way to increase disk performance would be to use Xen PV
disks. You just need to install the Windows PV drivers:

http://www.xenproject.org/developers/teams/windows-pv-drivers.html

But using VirtIO disk should also increase performance, even though
most probably not as much.

Cheers,

Stefano

On Tue, 15 Dec 2015, Luca Tongiani wrote:

Hi to all,
I'm writing you this mail for asking some advice about a great problem i'm havin in running a Windows VM
(HVM) onto a Xen (Gentoo based) Hypevisor.

I need to achieve maximum performance from this VM because of intense SQL tasks running in it.

I've seen good improvement in IO on disk using VirtIO on a Windows VM onto a QEMU (QNAP) hypervisor, and i'm
tryin to use this feature also on my Xen HV.
Is VirtIO disk a good way to improve performance?

Thx in advance and hope to keep in touch
--

Luca Tongiani

Sinte srl
Soluzioni Informatiche e Telematiche
via Monte Grappa 4/B
20900 Monza (MB)

Cel (+39) 339 745 49 21
Tel (+39) 039 200 59 60
Fax (+39) 039 200 69 42
Web www.sinte.net




--

Luca Tongiani

Sinte srl
Soluzioni Informatiche e Telematiche
via Monte Grappa 4/B
20900 Monza (MB)

Tel (+39) 039 200 59 60
Fax (+39) 039 200 69 42
Web www.sinte.net




--

Luca Tongiani

Sinte srl
Soluzioni Informatiche e Telematiche
via Monte Grappa 4/B
20900 Monza (MB)

Tel (+39) 039 200 59 60
Fax (+39) 039 200 69 42
Web www.sinte.net




--

Luca Tongiani

Sinte srl
Soluzioni Informatiche e Telematiche
via Monte Grappa 4/B
20900 Monza (MB)

Tel (+39) 039 200 59 60
Fax (+39) 039 200 69 42
Web www.sinte.net

--

Luca Tongiani

Sinte srl
Soluzioni Informatiche e Telematiche
via Monte Grappa 4/B
20900 Monza (MB)

Tel (+39) 039 200 59 60
Fax (+39) 039 200 69 42
Web www.sinte.net

--------------080901020107060303090507-- --------------020303070908090404020103 Content-Type: text/x-vcard; name="luca_tongiani.vcf" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="luca_tongiani.vcf" bnVsbA== --------------020303070908090404020103 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --------------020303070908090404020103--