Ido Levy
2008-Jul-28 17:15 UTC
[Xen-users] RHEL 5.2 i386 image - Xen kernel doesn''t recognize the total amount of system memory
Hello, We have installed RHEL 5.2 Server ( i386 image ) on a machine with 64GB of RAM. When booting the default PAE kernel ( 2.6.18-92.el5PAE ) that is shipped with RHEL 5.2 installation the OS detects 64GB of RAM. But when booting the Xen kernel ( 2.6.18-92.el5xen ) the OS detects only 14GB of the total amount of available RAM. Did anyone encounter this problem before ? Is it a normal behavior for a 32 bit image ? Thanks, Ido _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Tom Georgoulias
2008-Jul-28 20:45 UTC
Re: [Xen-users] RHEL 5.2 i386 image - Xen kernel doesn''t recognize the total amount of system memory
Ido Levy wrote:> We have installed RHEL 5.2 Server ( i386 image ) on a machine with 64GB of > RAM. > > When booting the default PAE kernel ( 2.6.18-92.el5PAE ) that is shipped > with RHEL 5.2 installation the OS detects 64GB of RAM. > But when booting the Xen kernel ( 2.6.18-92.el5xen ) the OS detects only > 14GB of the total amount of available RAM. > > Did anyone encounter this problem before ?I did when I first installed RHEL5.1 on a server with 32GB of RAM.> Is it a normal behavior for a 32 bit image ?Yes, 32-bit supports up to 16GB. To use the rest of the RAM, you''d need to install the 64-bit kernel-xen. Some docs are here: https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html Hope that helps. Tom _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Ido Levy
2008-Jul-29 11:02 UTC
Re: [Xen-users] RHEL 5.2 i386 image - Xen kernel doesn''t recognize the total amount of system memory
Tom,
Thanks for the info.
Do you know if RHEL 4.5/6 32 bit image Xen kernel supports more than 16GB
of RAM ?
Ido Levy
Tom Georgoulias
<tomg@mcclatchyin
teractive.com> To
Ido Levy/Haifa/IBM@IBMIL
28/07/2008 23:45 cc
xen-users@lists.xensource.com,
Alexandra Kisin/Haifa/IBM@IBMIL
Subject
Re: [Xen-users] RHEL 5.2 i386 image
- Xen kernel doesn''t recognize
the
total amount of system memory
Ido Levy wrote:
> We have installed RHEL 5.2 Server ( i386 image ) on a machine with 64GB
of> RAM.
>
> When booting the default PAE kernel ( 2.6.18-92.el5PAE ) that is shipped
> with RHEL 5.2 installation the OS detects 64GB of RAM.
> But when booting the Xen kernel ( 2.6.18-92.el5xen ) the OS detects only
> 14GB of the total amount of available RAM.
>
> Did anyone encounter this problem before ?
I did when I first installed RHEL5.1 on a server with 32GB of RAM.
> Is it a normal behavior for a 32 bit image ?
Yes, 32-bit supports up to 16GB. To use the rest of the RAM, you''d
need
to install the 64-bit kernel-xen. Some docs are here:
https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html
Hope that helps.
Tom
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Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users
aaron@crucialp.com
2008-Jul-29 11:06 UTC
Re: [Xen-users] RHEL 5.2 i386 image - Xen kernel doesn''t recognize the total amount of system memory
Hi Ido, We recently made multiple attempts to get Xen 32bit kernel (centos OS) using 32GB, and all were unsuccessful. The OS would only allow use of the first 16GB. We have since tested the same hardware on 64bit, and you can utilize all 32GB without any issues! Regards, Aaron Quoting Ido Levy <IDOL@il.ibm.com>:> Tom, > > Thanks for the info. > > Do you know if RHEL 4.5/6 32 bit image Xen kernel supports more than 16GB > of RAM ? > > Ido Levy > > > > > Tom Georgoulias > <tomg@mcclatchyin > teractive.com> To > Ido Levy/Haifa/IBM@IBMIL > 28/07/2008 23:45 cc > xen-users@lists.xensource.com, > Alexandra Kisin/Haifa/IBM@IBMIL > Subject > Re: [Xen-users] RHEL 5.2 i386 image > - Xen kernel doesn''t recognize the > total amount of system memory > > > > > > > > > > > Ido Levy wrote: > >> We have installed RHEL 5.2 Server ( i386 image ) on a machine with 64GB > of >> RAM. >> >> When booting the default PAE kernel ( 2.6.18-92.el5PAE ) that is shipped >> with RHEL 5.2 installation the OS detects 64GB of RAM. >> But when booting the Xen kernel ( 2.6.18-92.el5xen ) the OS detects only >> 14GB of the total amount of available RAM. >> >> Did anyone encounter this problem before ? > > I did when I first installed RHEL5.1 on a server with 32GB of RAM. > >> Is it a normal behavior for a 32 bit image ? > > Yes, 32-bit supports up to 16GB. To use the rest of the RAM, you''d need > to install the 64-bit kernel-xen. Some docs are here: > > https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html > > > Hope that helps. > > Tom > > > > _______________________________________________ > 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
Pasi Kärkkäinen
2008-Jul-29 12:32 UTC
Re: [Xen-users] RHEL 5.2 i386 image - Xen kernel doesn''t recognize the total amount of system memory
On Tue, Jul 29, 2008 at 06:06:40AM -0500, aaron@crucialp.com wrote:> Hi Ido, > > We recently made multiple attempts to get Xen 32bit kernel (centos OS) > using 32GB, and all were unsuccessful. The OS would only allow use of > the first 16GB. We have since tested the same hardware on 64bit, and > you can utilize all 32GB without any issues! >With RHEL 5.2 (and CentOS 5.2) you should be able to run 64b hypervisor with 32b domU''s.. so you could have 64b hypervisor (seeing all the memory) and split it between multiple 32b domU''s (and 32b dom0, if you want). Or then run 64b hypervisor + 64b dom0 + 32b domU''s. -- Pasi> Regards, > Aaron > > > Quoting Ido Levy <IDOL@il.ibm.com>: > > >Tom, > > > >Thanks for the info. > > > >Do you know if RHEL 4.5/6 32 bit image Xen kernel supports more than 16GB > >of RAM ? > > > >Ido Levy > > > > > > > > > > Tom Georgoulias > > <tomg@mcclatchyin > > teractive.com> To > > Ido Levy/Haifa/IBM@IBMIL > > 28/07/2008 23:45 cc > > xen-users@lists.xensource.com, > > Alexandra Kisin/Haifa/IBM@IBMIL > > Subject > > Re: [Xen-users] RHEL 5.2 i386 image > > - Xen kernel doesn''t recognize the > > total amount of system memory > > > > > > > > > > > > > > > > > > > > > >Ido Levy wrote: > > > >>We have installed RHEL 5.2 Server ( i386 image ) on a machine with 64GB > >of > >>RAM. > >> > >>When booting the default PAE kernel ( 2.6.18-92.el5PAE ) that is shipped > >>with RHEL 5.2 installation the OS detects 64GB of RAM. > >>But when booting the Xen kernel ( 2.6.18-92.el5xen ) the OS detects only > >>14GB of the total amount of available RAM. > >> > >>Did anyone encounter this problem before ? > > > >I did when I first installed RHEL5.1 on a server with 32GB of RAM. > > > >>Is it a normal behavior for a 32 bit image ? > > > >Yes, 32-bit supports up to 16GB. To use the rest of the RAM, you''d need > >to install the 64-bit kernel-xen. Some docs are here: > > > >https://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/en-US/RHEL510/Virtualization_Guide/ch-virt-hw-support.html > > > > > >Hope that helps. > > > >Tom > > > > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users