You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@cloudstack.apache.org by Lucas Hughes <lu...@ecommerce.com> on 2012/05/31 17:15:44 UTC
8 Xen hosts limitations
Hello,
I see in the install docs that it says not to use more than 8 Xen hosts
in one pool. I am wondering why this is the case because as a test I
added 10 hosts to a pool and Cloudstack is managing them without any
issues that I see. Any further clarification on this issue would be
greatly appreciated.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Nitin Mehta <Ni...@citrix.com>.
Lucas - I think this is more of a recommended guideline from the hypervisor to have a descent performance. From what I recall I think the performance of the cluster starts degrading exponentially as you scale the number of vlans and the hosts in the cluster.
Thanks,
-Nitin
-----Original Message-----
From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
Sent: Thursday, May 31, 2012 8:46 PM
To: cloudstack-users@incubator.apache.org; cloudstack-dev@incubator.apache.org
Subject: 8 Xen hosts limitations
Hello,
I see in the install docs that it says not to use more than 8 Xen hosts in one pool. I am wondering why this is the case because as a test I added 10 hosts to a pool and Cloudstack is managing them without any issues that I see. Any further clarification on this issue would be greatly appreciated.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Nitin Mehta <Ni...@citrix.com>.
Lucas - I think this is more of a recommended guideline from the hypervisor to have a descent performance. From what I recall I think the performance of the cluster starts degrading exponentially as you scale the number of vlans and the hosts in the cluster.
Thanks,
-Nitin
-----Original Message-----
From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
Sent: Thursday, May 31, 2012 8:46 PM
To: cloudstack-users@incubator.apache.org; cloudstack-dev@incubator.apache.org
Subject: 8 Xen hosts limitations
Hello,
I see in the install docs that it says not to use more than 8 Xen hosts in one pool. I am wondering why this is the case because as a test I added 10 hosts to a pool and Cloudstack is managing them without any issues that I see. Any further clarification on this issue would be greatly appreciated.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
Re: 8 Xen hosts limitations
Posted by Lucas Hughes <lu...@ecommerce.com>.
On 05/31/2012 01:46 PM, Anthony Xu wrote:
> Hi Clayton,
>
> You are right, 8 host is a rule of thumb, 16 is hard limitation.
> Cloudstack uses XAPI to communicate with XenServer Pool, CloudStack uses XAPI much more heavily than user uses XAPI though XenCenter/CLI,
> Which includes some regular XAPI call, like VM state Sync,
>
> We found if there are more than 8 host in a pool, it may cause XenServer host slow.
>
> It is a rule of thumb, which assumes you want to run more than ~200 VM on this XenServer pool.
>
> If you want to run big VM, the number of VMs in the XenServer pool is less than 100, I think you can add more host into a pool.
>
>
> Thanks,
> Anthony
>
>
>
>
>
>
>> -----Original Message-----
>> From: Clayton Weise [mailto:cweise@iswest.net]
>> Sent: Thursday, May 31, 2012 9:21 AM
>> To: 'cloudstack-dev@incubator.apache.org'; 'cloudstack-
>> users@incubator.apache.org'
>> Subject: RE: 8 Xen hosts limitations
>>
>> Somebody from Citrix/CloudStack can correct me here but as I understand
>> it 8 is a rule of thumb and not a strict law. That being said,
>> XenServer (and XCP) are limited to 16 hosts per resource pool -- and
>> that _is_ a hard limit. Other limits are available from here:
>> http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer
>> _6_Configuration_Limits.pdf
>>
>> -Clayton
>>
>> -----Original Message-----
>> From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
>> Sent: Thursday, May 31, 2012 8:16 AM
>> To: cloudstack-users@incubator.apache.org; cloudstack-
>> dev@incubator.apache.org
>> Subject: 8 Xen hosts limitations
>>
>> Hello,
>>
>> I see in the install docs that it says not to use more than 8 Xen hosts
>> in one pool. I am wondering why this is the case because as a test I
>> added 10 hosts to a pool and Cloudstack is managing them without any
>> issues that I see. Any further clarification on this issue would be
>> greatly appreciated.
>>
>> --
>> Lucas Hughes
>> Cloud Engineer
>> Ecommerce Inc
Thanks to all for the clarification.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
Re: 8 Xen hosts limitations
Posted by Lucas Hughes <lu...@ecommerce.com>.
On 05/31/2012 01:46 PM, Anthony Xu wrote:
> Hi Clayton,
>
> You are right, 8 host is a rule of thumb, 16 is hard limitation.
> Cloudstack uses XAPI to communicate with XenServer Pool, CloudStack uses XAPI much more heavily than user uses XAPI though XenCenter/CLI,
> Which includes some regular XAPI call, like VM state Sync,
>
> We found if there are more than 8 host in a pool, it may cause XenServer host slow.
>
> It is a rule of thumb, which assumes you want to run more than ~200 VM on this XenServer pool.
>
> If you want to run big VM, the number of VMs in the XenServer pool is less than 100, I think you can add more host into a pool.
>
>
> Thanks,
> Anthony
>
>
>
>
>
>
>> -----Original Message-----
>> From: Clayton Weise [mailto:cweise@iswest.net]
>> Sent: Thursday, May 31, 2012 9:21 AM
>> To: 'cloudstack-dev@incubator.apache.org'; 'cloudstack-
>> users@incubator.apache.org'
>> Subject: RE: 8 Xen hosts limitations
>>
>> Somebody from Citrix/CloudStack can correct me here but as I understand
>> it 8 is a rule of thumb and not a strict law. That being said,
>> XenServer (and XCP) are limited to 16 hosts per resource pool -- and
>> that _is_ a hard limit. Other limits are available from here:
>> http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer
>> _6_Configuration_Limits.pdf
>>
>> -Clayton
>>
>> -----Original Message-----
>> From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
>> Sent: Thursday, May 31, 2012 8:16 AM
>> To: cloudstack-users@incubator.apache.org; cloudstack-
>> dev@incubator.apache.org
>> Subject: 8 Xen hosts limitations
>>
>> Hello,
>>
>> I see in the install docs that it says not to use more than 8 Xen hosts
>> in one pool. I am wondering why this is the case because as a test I
>> added 10 hosts to a pool and Cloudstack is managing them without any
>> issues that I see. Any further clarification on this issue would be
>> greatly appreciated.
>>
>> --
>> Lucas Hughes
>> Cloud Engineer
>> Ecommerce Inc
Thanks to all for the clarification.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Anthony Xu <Xu...@citrix.com>.
Hi Clayton,
You are right, 8 host is a rule of thumb, 16 is hard limitation.
Cloudstack uses XAPI to communicate with XenServer Pool, CloudStack uses XAPI much more heavily than user uses XAPI though XenCenter/CLI,
Which includes some regular XAPI call, like VM state Sync,
We found if there are more than 8 host in a pool, it may cause XenServer host slow.
It is a rule of thumb, which assumes you want to run more than ~200 VM on this XenServer pool.
If you want to run big VM, the number of VMs in the XenServer pool is less than 100, I think you can add more host into a pool.
Thanks,
Anthony
> -----Original Message-----
> From: Clayton Weise [mailto:cweise@iswest.net]
> Sent: Thursday, May 31, 2012 9:21 AM
> To: 'cloudstack-dev@incubator.apache.org'; 'cloudstack-
> users@incubator.apache.org'
> Subject: RE: 8 Xen hosts limitations
>
> Somebody from Citrix/CloudStack can correct me here but as I understand
> it 8 is a rule of thumb and not a strict law. That being said,
> XenServer (and XCP) are limited to 16 hosts per resource pool -- and
> that _is_ a hard limit. Other limits are available from here:
> http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer
> _6_Configuration_Limits.pdf
>
> -Clayton
>
> -----Original Message-----
> From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
> Sent: Thursday, May 31, 2012 8:16 AM
> To: cloudstack-users@incubator.apache.org; cloudstack-
> dev@incubator.apache.org
> Subject: 8 Xen hosts limitations
>
> Hello,
>
> I see in the install docs that it says not to use more than 8 Xen hosts
> in one pool. I am wondering why this is the case because as a test I
> added 10 hosts to a pool and Cloudstack is managing them without any
> issues that I see. Any further clarification on this issue would be
> greatly appreciated.
>
> --
> Lucas Hughes
> Cloud Engineer
> Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Anthony Xu <Xu...@citrix.com>.
Hi Clayton,
You are right, 8 host is a rule of thumb, 16 is hard limitation.
Cloudstack uses XAPI to communicate with XenServer Pool, CloudStack uses XAPI much more heavily than user uses XAPI though XenCenter/CLI,
Which includes some regular XAPI call, like VM state Sync,
We found if there are more than 8 host in a pool, it may cause XenServer host slow.
It is a rule of thumb, which assumes you want to run more than ~200 VM on this XenServer pool.
If you want to run big VM, the number of VMs in the XenServer pool is less than 100, I think you can add more host into a pool.
Thanks,
Anthony
> -----Original Message-----
> From: Clayton Weise [mailto:cweise@iswest.net]
> Sent: Thursday, May 31, 2012 9:21 AM
> To: 'cloudstack-dev@incubator.apache.org'; 'cloudstack-
> users@incubator.apache.org'
> Subject: RE: 8 Xen hosts limitations
>
> Somebody from Citrix/CloudStack can correct me here but as I understand
> it 8 is a rule of thumb and not a strict law. That being said,
> XenServer (and XCP) are limited to 16 hosts per resource pool -- and
> that _is_ a hard limit. Other limits are available from here:
> http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer
> _6_Configuration_Limits.pdf
>
> -Clayton
>
> -----Original Message-----
> From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
> Sent: Thursday, May 31, 2012 8:16 AM
> To: cloudstack-users@incubator.apache.org; cloudstack-
> dev@incubator.apache.org
> Subject: 8 Xen hosts limitations
>
> Hello,
>
> I see in the install docs that it says not to use more than 8 Xen hosts
> in one pool. I am wondering why this is the case because as a test I
> added 10 hosts to a pool and Cloudstack is managing them without any
> issues that I see. Any further clarification on this issue would be
> greatly appreciated.
>
> --
> Lucas Hughes
> Cloud Engineer
> Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Clayton Weise <cw...@iswest.net>.
Somebody from Citrix/CloudStack can correct me here but as I understand it 8 is a rule of thumb and not a strict law. That being said, XenServer (and XCP) are limited to 16 hosts per resource pool -- and that _is_ a hard limit. Other limits are available from here: http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer_6_Configuration_Limits.pdf
-Clayton
-----Original Message-----
From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
Sent: Thursday, May 31, 2012 8:16 AM
To: cloudstack-users@incubator.apache.org; cloudstack-dev@incubator.apache.org
Subject: 8 Xen hosts limitations
Hello,
I see in the install docs that it says not to use more than 8 Xen hosts
in one pool. I am wondering why this is the case because as a test I
added 10 hosts to a pool and Cloudstack is managing them without any
issues that I see. Any further clarification on this issue would be
greatly appreciated.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc
RE: 8 Xen hosts limitations
Posted by Clayton Weise <cw...@iswest.net>.
Somebody from Citrix/CloudStack can correct me here but as I understand it 8 is a rule of thumb and not a strict law. That being said, XenServer (and XCP) are limited to 16 hosts per resource pool -- and that _is_ a hard limit. Other limits are available from here: http://www.citrix.com/site/resources/dynamic/salesdocs/Citrix_XenServer_6_Configuration_Limits.pdf
-Clayton
-----Original Message-----
From: Lucas Hughes [mailto:lucas.hughes@ecommerce.com]
Sent: Thursday, May 31, 2012 8:16 AM
To: cloudstack-users@incubator.apache.org; cloudstack-dev@incubator.apache.org
Subject: 8 Xen hosts limitations
Hello,
I see in the install docs that it says not to use more than 8 Xen hosts
in one pool. I am wondering why this is the case because as a test I
added 10 hosts to a pool and Cloudstack is managing them without any
issues that I see. Any further clarification on this issue would be
greatly appreciated.
--
Lucas Hughes
Cloud Engineer
Ecommerce Inc