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Ido Levy

2008-Aug-28 08:53 UTC

[Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount of physical memory

Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido


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

Robert Dunkley

2008-Aug-28 09:07 UTC

head link

RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system. 

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max. 

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
ofphysical memory


Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido


_______________________________________________
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
SEMTEC Limited trading as SAQ is 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.
DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit : Backups :
Managed Networks : Remote Support.

Find us in http://www.thebestof.co.uk/petersfield


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

Juan Pablo Rojas Jiménez

2008-Aug-28 11:14 UTC

head link

Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount ofphysical memory

Hi,

as far as i know, memory limits come from the compilation time options 
in the kernel...

I guess that 2.6 kernels, in order to ''view'' more than 4Gb of
memory,
need to have CONFIG_HIGHMEM64G=y  enabled, so i would say that they can 
see at least 64Gb :)

Hope this helps,

Juan Pablo

Robert Dunkley escribió:> >From what I have read the XenServer distribution can support up to 32GB
> RAM per VM and 128GB for the whole system. 
>
> My guess is that unless a deliberate restriction is put in place the
> limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
> VM is probably the max. 
>
> Anyone know for sure?
>
> -----Original Message-----
> From: xen-users-bounces@lists.xensource.com
> [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
> Sent: 28 August 2008 09:54
> To: xen-users@lists.xensource.com
> Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
> ofphysical memory
>
>
> Hello All,
>
> Does anyone know what is the current status of RHEL 5.2 x86_64 with
> respect
> to the maximum amount of RAM detected by the Xen 64 bit kernel
> (the one that shipped with Red Hat distribution )
>
> In the following link
> https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
> 10/Virtualization_Guide/ch-virt-hw-support.html
> it states that 32GB of RAM is the maximum amount of physical memory the
> Xen
> kernel can detect. Is it still the updated status ?
>
> Is there a work around or any other way to overcome this limit ?
>
> Any info would be appreciated
>
> Thanks,
>
> Ido
>
>
> _______________________________________________
> 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
> SEMTEC Limited trading as SAQ is 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.
> DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit :
Backups : Managed Networks : Remote Support.
>
> Find us in http://www.thebestof.co.uk/petersfield
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>   

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

tom.ashley@gmail.com

2008-Aug-28 11:14 UTC

head link

Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amountofphysical memory

Bog standard out of the box, I have a 64 bit centos 5.2 holding and recognising
64GB RAM happily. RHEL should be able to do the same.
Sent using BlackBerry® from Orange

-----Original Message-----
From: "Robert Dunkley" <Robert@saq.co.uk>

Date: Thu, 28 Aug 2008 10:07:33 
To: Ido Levy<IDOL@il.ibm.com>
Cc: <Xen-users@lists.xensource.com>
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn't detect all amount
	ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system. 

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max. 

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn't detect all amount
ofphysical memory

Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido

_______________________________________________
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
SEMTEC Limited trading as SAQ is 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.
DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit : Backups :
Managed Networks : Remote Support.

Find us in http://www.thebestof.co.uk/petersfield

_______________________________________________
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

Robert Dunkley

2008-Aug-28 11:24 UTC

head link

RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amountofphysical memory

Hi,

I got a reply from RedHat support (Only emailed poster and not the list
initially). Max for RHEL Xen kernel is same as standard Kernel (1Tb for
X64) but max mem per VM is limited to 32Gb.

Reassuring to hear though, I was a bit worried that updating our Centos
5.2 systems from 32Gb Ram to 128Gb might not work :)


Rob

-----Original Message-----
From: tom.ashley@gmail.com [mailto:tom.ashley@gmail.com] 
Sent: 28 August 2008 12:15
To: Robert Dunkley; xen-users-bounces@lists.xensource.com; Ido Levy
Cc: Xen-users@lists.xensource.com
Subject: Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all
amountofphysical memory

Bog standard out of the box, I have a 64 bit centos 5.2 holding and
recognising 64GB RAM happily. RHEL should be able to do the same.
Sent using BlackBerry(r) from Orange

-----Original Message-----
From: "Robert Dunkley" <Robert@saq.co.uk>

Date: Thu, 28 Aug 2008 10:07:33 
To: Ido Levy<IDOL@il.ibm.com>
Cc: <Xen-users@lists.xensource.com>
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
	ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system. 

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max. 

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
ofphysical memory


Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido


_______________________________________________
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
SEMTEC Limited trading as SAQ is 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.
DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit :
Backups : Managed Networks : Remote Support.

Find us in http://www.thebestof.co.uk/petersfield


_______________________________________________
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

Ido Levy

2008-Aug-28 11:57 UTC

head link

RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount of physical memory

Hi,

Thank you all for your replies.

The reason I brought up this issue is that currently I have a machine with
64GB RAM installed with RHEL 5.2 i386 version.
When using the PAE kernel the OS detects the total amount of memory, but
when using the Xen kernel that shipped with this Red Hat distribution it
detects only 14GB of RAM

I was wondering if I will install the x86_64 version of RHEL 5.2 will it
detects more memory.

Any help figure out what is the issue will be appreciated.
In addition I would be happy to provide the info to the guy from the Red
Hat support team.

Thanks

Ido



                                                                           
             "Robert Dunkley"
             <Robert@saq.co.uk                                             
             >                                                          To 
             Sent by:                  <tom.ashley@gmail.com>
             xen-users-bounces                                          cc 
             @lists.xensource.         Xen-users@lists.xensource.com       
             com                                                   Subject 
                                       RE: [Xen-users] RHEL 5.2 Xen Kernel 
                                       doesn''t detect all
             08/28/2008 02:24          amountofphysical memory             
             PM                                                            
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Hi,

I got a reply from RedHat support (Only emailed poster and not the list
initially). Max for RHEL Xen kernel is same as standard Kernel (1Tb for
X64) but max mem per VM is limited to 32Gb.

Reassuring to hear though, I was a bit worried that updating our Centos
5.2 systems from 32Gb Ram to 128Gb might not work :)


Rob

-----Original Message-----
From: tom.ashley@gmail.com [?mailto:tom.ashley@gmail.com]
Sent: 28 August 2008 12:15
To: Robert Dunkley; xen-users-bounces@lists.xensource.com; Ido Levy
Cc: Xen-users@lists.xensource.com
Subject: Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all
amountofphysical memory

Bog standard out of the box, I have a 64 bit centos 5.2 holding and
recognising 64GB RAM happily. RHEL should be able to do the same.
Sent using BlackBerry(r) from Orange

-----Original Message-----
From: "Robert Dunkley" <Robert@saq.co.uk>

Date: Thu, 28 Aug 2008 10:07:33
To: Ido Levy<IDOL@il.ibm.com>
Cc: <Xen-users@lists.xensource.com>
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
             ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system.

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max.

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[?mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
ofphysical memory


Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido


_______________________________________________
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
SEMTEC Limited trading as SAQ is 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.
DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit :
Backups : Managed Networks : Remote Support.

Find us in http://www.thebestof.co.uk/petersfield


_______________________________________________
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



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

Robert Dunkley

2008-Aug-28 12:00 UTC

head link

RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount of physical memory

Yes, install the X64 version and it should see all 64Gb of RAM.

-----Original Message-----
From: Ido Levy [mailto:IDOL@il.ibm.com] 
Sent: 28 August 2008 12:58
To: Robert Dunkley
Cc: tom.ashley@gmail.com; Xen-users@lists.xensource.com;
xen-users-bounces@lists.xensource.com
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
of physical memory

Hi,

Thank you all for your replies.

The reason I brought up this issue is that currently I have a machine
with
64GB RAM installed with RHEL 5.2 i386 version.
When using the PAE kernel the OS detects the total amount of memory, but
when using the Xen kernel that shipped with this Red Hat distribution it
detects only 14GB of RAM

I was wondering if I will install the x86_64 version of RHEL 5.2 will it
detects more memory.

Any help figure out what is the issue will be appreciated.
In addition I would be happy to provide the info to the guy from the Red
Hat support team.

Thanks

Ido

             "Robert Dunkley"

             <Robert@saq.co.uk

             >
To 
             Sent by:                  <tom.ashley@gmail.com>

             xen-users-bounces
cc 
             @lists.xensource.         Xen-users@lists.xensource.com

             com
Subject 
                                       RE: [Xen-users] RHEL 5.2 Xen
Kernel 
                                       doesn''t detect all

             08/28/2008 02:24          amountofphysical memory

             PM

Hi,

I got a reply from RedHat support (Only emailed poster and not the list
initially). Max for RHEL Xen kernel is same as standard Kernel (1Tb for
X64) but max mem per VM is limited to 32Gb.

Reassuring to hear though, I was a bit worried that updating our Centos
5.2 systems from 32Gb Ram to 128Gb might not work :)

Rob

-----Original Message-----
From: tom.ashley@gmail.com [?mailto:tom.ashley@gmail.com]
Sent: 28 August 2008 12:15
To: Robert Dunkley; xen-users-bounces@lists.xensource.com; Ido Levy
Cc: Xen-users@lists.xensource.com
Subject: Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all
amountofphysical memory

Bog standard out of the box, I have a 64 bit centos 5.2 holding and
recognising 64GB RAM happily. RHEL should be able to do the same.
Sent using BlackBerry(r) from Orange

-----Original Message-----
From: "Robert Dunkley" <Robert@saq.co.uk>

Date: Thu, 28 Aug 2008 10:07:33
To: Ido Levy<IDOL@il.ibm.com>
Cc: <Xen-users@lists.xensource.com>
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
             ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system.

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max.

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[?mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
ofphysical memory

Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido

_______________________________________________
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
SEMTEC Limited trading as SAQ is 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.
DSL : Domains : Email : Hosting : CoLo : Servers : Racks : Transit :
Backups : Managed Networks : Remote Support.

Find us in http://www.thebestof.co.uk/petersfield

_______________________________________________
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

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

Dustin Henning

2008-Aug-28 13:59 UTC

head link

RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount of physical memory

It seems unlikely that this is related, but see this bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=250299
I had this problem in F7, F8 (apparently it still exists in F9 as well),
CentOS 5.2, and maybe CentOS 5.3 (probably exists there, but I don''t
remember if I''ve tried it).
In each case where I experienced the issue, the patch for grub solved the
problem.
This issue only seems to happen on certain BIOSes, and even then the stock
kernels work fine, but the Xen ones don''t.
The reason I doubt it is related is I haven''t tried it on PAE, only
x86_64,
and I believe the memory was limited to 3.2 GiB, not 14 like your issue.
However, I figured I''d mention this in case you have the same problem
(probably 3.2 GiB vs 14) when you go to x86_64 and find the patch solves it
(or in case you feel bold and daring and try it even where it seems
unrelated and find it to work).  Mentioning it to the support guy might get
it fixed upstream (since bugzilla reports for F7, F8, and F9 haven''t to
the
best of my knowledge), though it seems like bugzilla should do that if it
were going to be fixed upstream at all.
	Dustin

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: Thursday, August 28, 2008 07:58
To: Robert Dunkley
Cc: tom.ashley@gmail.com; Xen-users@lists.xensource.com;
xen-users-bounces@lists.xensource.com
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
of
physical memory

Hi,

Thank you all for your replies.

The reason I brought up this issue is that currently I have a machine with
64GB RAM installed with RHEL 5.2 i386 version.
When using the PAE kernel the OS detects the total amount of memory, but
when using the Xen kernel that shipped with this Red Hat distribution it
detects only 14GB of RAM

I was wondering if I will install the x86_64 version of RHEL 5.2 will it
detects more memory.

Any help figure out what is the issue will be appreciated.
In addition I would be happy to provide the info to the guy from the Red
Hat support team.

Thanks

Ido



                                                                           
             "Robert Dunkley"
             <Robert@saq.co.uk                                             
             >                                                          To 
             Sent by:                  <tom.ashley@gmail.com>
             xen-users-bounces                                          cc 
             @lists.xensource.         Xen-users@lists.xensource.com       
             com                                                   Subject 
                                       RE: [Xen-users] RHEL 5.2 Xen Kernel 
                                       doesn''t detect all
             08/28/2008 02:24          amountofphysical memory             
             PM                                                            
                                                                           
                                                                           
                                                                           
                                                                           
                                                                           




Hi,

I got a reply from RedHat support (Only emailed poster and not the list
initially). Max for RHEL Xen kernel is same as standard Kernel (1Tb for
X64) but max mem per VM is limited to 32Gb.

Reassuring to hear though, I was a bit worried that updating our Centos
5.2 systems from 32Gb Ram to 128Gb might not work :)


Rob

-----Original Message-----
From: tom.ashley@gmail.com [?mailto:tom.ashley@gmail.com]
Sent: 28 August 2008 12:15
To: Robert Dunkley; xen-users-bounces@lists.xensource.com; Ido Levy
Cc: Xen-users@lists.xensource.com
Subject: Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all
amountofphysical memory

Bog standard out of the box, I have a 64 bit centos 5.2 holding and
recognising 64GB RAM happily. RHEL should be able to do the same.
Sent using BlackBerry(r) from Orange

-----Original Message-----
From: "Robert Dunkley" <Robert@saq.co.uk>

Date: Thu, 28 Aug 2008 10:07:33
To: Ido Levy<IDOL@il.ibm.com>
Cc: <Xen-users@lists.xensource.com>
Subject: RE: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
             ofphysical memory

>From what I have read the XenServer distribution can support up to 32GBRAM per VM and 128GB for the whole system.

My guess is that unless a deliberate restriction is put in place the
limits RAM for RHEL5 Xen kernel then 256Gb RAM in total and 32Gb RAM per
VM is probably the max.

Anyone know for sure?

-----Original Message-----
From: xen-users-bounces@lists.xensource.com
[?mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Ido Levy
Sent: 28 August 2008 09:54
To: xen-users@lists.xensource.com
Subject: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount
ofphysical memory


Hello All,

Does anyone know what is the current status of RHEL 5.2 x86_64 with
respect
to the maximum amount of RAM detected by the Xen 64 bit kernel
(the one that shipped with Red Hat distribution )

In the following link
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL5
10/Virtualization_Guide/ch-virt-hw-support.html
it states that 32GB of RAM is the maximum amount of physical memory the
Xen
kernel can detect. Is it still the updated status ?

Is there a work around or any other way to overcome this limit ?

Any info would be appreciated

Thanks,

Ido


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Sadique Puthen

2008-Aug-28 14:46 UTC

head link

Re: [Xen-users] RHEL 5.2 Xen Kernel doesn''t detect all amount of physical memory

Ido Levy wrote:> Hello All,
>
> Does anyone know what is the current status of RHEL 5.2 x86_64 with respect
> to the maximum amount of RAM detected by the Xen 64 bit kernel
> (the one that shipped with Red Hat distribution )
>
> In the following link
>
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html
> it states that 32GB of RAM is the maximum amount of physical memory the Xen
> kernel can detect. Is it still the updated status ?
>   
>From RHEL-5.2 release note athttps://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.2/html/Release_Notes/x86_64/ar01s06.html

"The hypervisor can now support up to 512GB of memory. To ensure that
the system properly detects and uses this much memory, boot the
virtualized kernel with the parameter |xenheap_megabytes=64|."

There is currently a limitation of 16GB memory on 32 bit hypervisor. So
u should use a 64bit version of RHEL to see all the 64GB of memory.

--Sadique
> Is there a work around or any other way to overcome this limit ?
>
> Any info would be appreciated
>
> Thanks,
>
> Ido
>
>
> _______________________________________________
> Xen-users mailing list
> Xen-users@lists.xensource.com
> http://lists.xensource.com/xen-users
>
>   

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