From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Mr. Teo En Ming (Zhang Enming)" Subject: Re: Max. PV and HVM Guests Date: Mon, 9 Nov 2009 18:52:37 +0800 Message-ID: References: <1257685302.5339.11.camel@k2000.jpp.fr> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0497915306==" Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-users-bounces@lists.xensource.com Errors-To: xen-users-bounces@lists.xensource.com To: Robert Dunkley Cc: xen-devel@lists.xensource.com, space.time.universe@gmail.com, xen-users@lists.xensource.com List-Id: xen-devel@lists.xenproject.org --===============0497915306== Content-Type: multipart/alternative; boundary=001485f6c360e9a9bf0477edfd51 --001485f6c360e9a9bf0477edfd51 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi, Please watch this 4-minute video at http://www.youtube.com/watch?v=3DLbLaPpwNAx4 I have only started 3 HVM Linux guests with 1 GB ram each. I can't start th= e 4th HVM guest. If I attempt to start the 4th instance, it will crash dom0. Are there anything in the xm dmesg output that could explain the low limit to the number of VMs that I could start before dom0 becomes unresponsive? Thank you. --=20 Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical Engineering) Alma Maters: (1) Singapore Polytechnic (2) National University of Singapore My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com My Secondary Blog: http://enmingteo.wordpress.com My Youtube videos: http://www.youtube.com/user/enmingteo Email: space.time.universe@gmail.com Mobile Phone (Starhub Prepaid): +65-8369-2618 Street: Bedok Reservoir Road Country: Singapore On Mon, Nov 9, 2009 at 4:17 PM, Robert Dunkley wrote: > There seems to also be a limit imposed by CPU context switching. Ie. Once > you have enough VMs trying to grab a cpu core things come to a standstill= as > the cpu spends most of its time switching rather than processing. The mos= t > common bottleneck I find is disk performance but this depends hugely on w= hat > your VMs are doing. > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto: > xen-users-bounces@lists.xensource.com] On Behalf Of Moi meme > Sent: 08 November 2009 13:02 > To: Mr. Teo En Ming (Zhang Enming) > Cc: xen-devel@lists.xensource.com; xen-users@lists.xensource.com > Subject: Re: [Xen-users] Max. PV and HVM Guests > > Hello, > > The maximum is a direct function of the available memory, every new > machine "eats" some memory and when there is no more memory ...... > I had some servers (64bits, 2 quad core and 32Gb Ram) running 19 VM, > 2003 server, 2000 Server,Fedora, Debian all in 32bits. > In my own system I have tested with upto 10 VMs of 512M each without > breaking the system. > > Regards > > JP Pozzi > > Le dimanche 08 novembre 2009 =E0 19:45 +0800, Mr. Teo En Ming (Zhang > Enming) a =E9crit : > > Hi, > > > > I have observed that there is a maximum limit to the number of PV or > > HVM virtual machines you can start before dom0 hangs or crashes. > > > > For Fedora 11 Linux x86-64 PV guests, dom0 will crash when I start the > > 7th instance. Max I can start is 6 without crashing. > > > > For CentOS 5.2 Linux x86-64 HVM guests, dom0 will crash when I start > > the 4th instance. Max I can start is 3 without crashing. > > > > I have 6 GB of DDR2-800 with Intel Pentium Dual Core E6300 2.8 GHz on > > Intel DQ45CB motherboard. > > > > Are the above limits reasonable considering the hardware > > specifications of my computer? > > > > I am using Xen 3.5-unstable changeset 20143 with pv-ops dom0 kernels > > 2.6.30-rc3, 2.6.31-rc6, 2.6.31.1, 2.6.31.4, and 2.6.31.5. My host > > operating system is Fedora 11 Linux x86-64. > > > > -- > > Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical > > Engineering) > > Alma Maters: > > (1) Singapore Polytechnic > > (2) National University of Singapore > > My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com > > My Secondary Blog: http://enmingteo.wordpress.com > > My Youtube videos: http://www.youtube.com/user/enmingteo > > Email: space.time.universe@gmail.com > > Mobile Phone (Starhub Prepaid): +65-8369-2618 > > Street: Bedok Reservoir Road > > Country: Singapore > > _______________________________________________ > > 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 > > The SAQ Group > > Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ > SAQ is the trading name of SEMTEC Limited. Registered in England & Wales > Company Number: 06481952 > > http://www.saqnet.co.uk AS29219 > > SAQ Group Delivers high quality, honestly priced communication and I.T. > services to UK Business. > > Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : Transit = : > Backups : Managed Networks : Remote Support. > > ISPA Member > > --001485f6c360e9a9bf0477edfd51 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi,

Please watch this 4-minute video at http://www.youtube.com/watch?v=3DLbLaPpwNAx4

I have only started 3 HVM Linux guests with 1 GB ram each. I can&= #39;t start the 4th HVM guest. If I attempt to start the 4th instance, it w= ill crash dom0.

Are there anything in the xm dmesg output that could explain the low li= mit to the number of VMs that I could start before dom0 becomes unresponsiv= e?

Thank you.

--
Mr. Teo En Ming (Zhang Enming) Dip(Mecha= tronics) BEng(Hons)(Mechanical Engineering)
Alma Maters:
(1) Singapore Polytechnic
(2) National University of Sin= gapore
My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com
My Sec= ondary Blog: http://enmingteo.wo= rdpress.com
My Youtube videos: http:/= /www.youtube.com/user/enmingteo
Email: space.time.universe@gmail.com
Mobile Phone (Star= hub Prepaid): +65-8369-2618
Street: Bedok Reservoir Road
Country: Singapore

On Mon, Nov 9, 2009 at 4:17 PM, Robert Dunkley = <Robert@saq.co.uk> wro= te:
There seems to al= so be a limit imposed by CPU context switching. Ie. Once you have enough VM= s trying to grab a cpu core things come to a standstill as the cpu spends m= ost of its time switching rather than processing. The most common bottlenec= k I find is disk performance but this depends hugely on what your VMs are d= oing.

-----Original Message-----
From: xen-users-bo= unces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of= Moi meme
Sent: 08 November 2009 13:02
To: Mr. Teo En Ming (Zhang Enming)
Cc: xen-devel@lists.xensou= rce.com; xen-users@lis= ts.xensource.com
Subject: Re: [Xen-users] Max. PV and HVM Guests

Hello,

The maximum is a direct function of the available memory, every new
machine "eats" some memory and when there is no more memory .....= .
I had some servers (64bits, 2 quad core and 32Gb Ram) running 19 VM,
2003 server, 2000 Server,Fedora, Debian all in 32bits.
In my own system I have tested with upto 10 VMs of 512M each without
breaking the system.

Regards

JP Pozzi

Le dimanche 08 novembre 2009 =E0 19:45 +0800, Mr. Teo En Ming (Zhang
Enming) a =E9crit :
> Hi,
>
> I have observed that there is a maximum limit to the number of PV or > HVM virtual machines you can start before dom0 hangs or crashes.
>
> For Fedora 11 Linux x86-64 PV guests, dom0 will crash when I start the=
> 7th instance. Max I can start is 6 without crashing.
>
> For CentOS 5.2 Linux x86-64 HVM guests, dom0 will crash when I start > the 4th instance. Max I can start is 3 without crashing.
>
> I have 6 GB of DDR2-800 with Intel Pentium Dual Core E6300 2.8 GHz on<= br> > Intel DQ45CB motherboard.
>
> Are the above limits reasonable considering the hardware
> specifications of my computer?
>
> I am using Xen 3.5-unstable changeset 20143 with pv-ops dom0 kernels > 2.6.30-rc3, 2.6.31-rc6, 2.6.31.1, 2.6.31.4, and 2.6.31.5. My host
> operating system is Fedora 11 Linux x86-64.
>
> --
> Mr. Teo En Ming (Zhang Enming) Dip(Mechatronics) BEng(Hons)(Mechanical=
> Engineering)
> Alma Maters:
> (1) Singapore Polytechnic
> (2) National University of Singapore
> My Primary Blog: http://teo-en-ming-aka-zhang-enming.blogspot.com<= /a>
> My Secondary Blog: http://enmingteo.wordpress.com
> My Youtube videos: http://www.youtube.com/user/enmingteo
> Email: space.time.uni= verse@gmail.com
> Mobile Phone (Starhub Prepaid): +65-8369-2618
> Street: Bedok Reservoir Road
> Country: Singapore
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xenso= urce.com
> htt= p://lists.xensource.com/xen-users




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

The SAQ Group

Registered Office: 18 Chapel Street, Petersfield, Hampshire GU32 3DZ
SAQ is the trading name of SEMTEC Limited. Registered in England & Wale= s
Company Number: 06481952

http://www.saqnet.co.= uk AS29219

SAQ Group Delivers high quality, honestly priced communication and I.T. ser= vices to UK Business.

Broadband : Domains : Email : Hosting : CoLo : Servers : Racks : Transit : = Backups : Managed Networks : Remote Support.

ISPA Member





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