Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
what kernel are you running?
On Mon, Dec 7, 2009 at 2:05 PM, Diederick Stoffers d.stoffers@gmail.com wrote:
Hi, We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it? Many Thanks, Diederick _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
[root@localhost ~]# uname -a Linux localhost.localdomain 2.6.18-164.6.1.el5xen #1 SMP Tue Nov 3 16:48:13 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
On 7 dec 2009, at 13:12, Rudi Ahlers wrote:
what kernel are you running?
On Mon, Dec 7, 2009 at 2:05 PM, Diederick Stoffers d.stoffers@gmail.com wrote:
Hi, We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it? Many Thanks, Diederick _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
-- Kind Regards Rudi Ahlers CEO, SoftDux Hosting Web: http://www.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
On 12/7/2009 7:24 AM, Diederick Stoffers wrote:
[root@localhost ~]# uname -a Linux localhost.localdomain 2.6.18-164.6.1.el5xen #1 SMP Tue Nov 3 16:48:13 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
If you dig back through the xen-users mailing list, there's a thread that discusses this recently. Look for a subject of "[Xen-users] Memory not seen in Dom0" back around Nov 8th. I tried to get GMane's web interface to toss up a direct link to the thread, but gave up.
nntp://news.gmane.org/gmane.comp.emulators.xen.user
Supposedly, it's not an issue unless you really really want >32GB in the Dom0 host. The Xen 64bit kernel (currently?) limits the Dom0 to 32GB. But any guest VMs that you create will initially use the RAM not used by the Dom0.
Most folks recommend that you limit Dom0's memory usage in grub.conf (using the dom0_mem= argument). Or you can set it later using "xm mem-set 0 ###M".
On Mon, Dec 7, 2009 at 12:24 PM, Diederick Stoffers d.stoffers@gmail.com wrote:
[root@localhost ~]# uname -a Linux localhost.localdomain 2.6.18-164.6.1.el5xen #1 SMP Tue Nov 3 16:48:13 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
On 7 dec 2009, at 13:12, Rudi Ahlers wrote:
what kernel are you running?
On Mon, Dec 7, 2009 at 2:05 PM, Diederick Stoffers d.stoffers@gmail.com wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64
bits version of Fedora 12 lists the correct amount of 128GB, CentOS only
finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS
(most of the software we use is specifically designed for CentOS). Does
anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
-- Kind Regards Rudi Ahlers CEO, SoftDux Hosting Web: http://www.SoftDux.com Office: 087 805 9573 Cell: 082 554 7532 _______________________________________________ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Try to run xentop (xm top) and see if it displays the correct ammount of memory.
On Mon, Dec 7, 2009 at 4:35 PM, Lucian @ lastdot.org lucian@lastdot.orgwrote:
On Mon, Dec 7, 2009 at 12:24 PM, Diederick Stoffers d.stoffers@gmail.com wrote:
[root@localhost ~]# uname -a Linux localhost.localdomain 2.6.18-164.6.1.el5xen #1 SMP Tue Nov 3
16:48:13
EST 2009 x86_64 x86_64 x86_64 GNU/Linux
On 7 dec 2009, at 13:12, Rudi Ahlers wrote:
what kernel are you running?
On Mon, Dec 7, 2009 at 2:05 PM, Diederick Stoffers <d.stoffers@gmail.com
wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64
bits version of Fedora 12 lists the correct amount of 128GB, CentOS only
finds 32GB (and so does Scientific Linux). I would much prefer to use
CentOS
(most of the software we use is specifically designed for CentOS). Does
anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
From: http://www.redhat.com/docs/manuals/enterprise/RHEL-5-manual/Virtualization-e...
"The Red Hat Enterprise Linux Virtualization kernel does not support more than 32GB of memory for x86_64 systems. If you need to boot the virtualization kernel on systems with more than 32GB of physical memory installed, you must append the kernel command line with mem=32G. This example shows how to enable the proper parameters in the grub.conf file:
title Red Hat Enterprise Linux Server (2.6.18-4.elxen) root (hd0, 0) kernel /xen.gz-2.6.18-4-el5 mem=32G module /vmlinuz -2.6.18-4.el5xen ro root=LABEL=/ module /initrd-2.6.18-4.el5xen.img"
Hi, It seems that this links shed light on the question: http://lists.xensource.com/archives/html/xen-users/2008-08/msg00934.html http://www.centos.org/docs/5/html/5.1/Virtualization_Guide/ch-virt-hw-suppor...
On 12/07/2009 02:05 PM, Diederick Stoffers wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Thanks! Virtualisation limits RAM to 32GB, removing this from the package does the trick.
Cheers,
Diederick
On 7 dec 2009, at 13:35, Nickolay Bunev wrote:
Hi, It seems that this links shed light on the question: http://lists.xensource.com/archives/html/xen-users/2008-08/msg00934.html http://www.centos.org/docs/5/html/5.1/Virtualization_Guide/ch-virt-hw-suppor...
On 12/07/2009 02:05 PM, Diederick Stoffers wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Diederick Stoffers wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
Hi
Very strange. I have a Dell Precision T7500 with 48GB of memory and CentOS-5.4 finds everything: kalyke (Linux)$ uname -rm; free 2.6.18-164.6.1.el5 x86_64 total used free shared buffers cached Mem: 49453972 48273592 1180380 0 219116 41775056 -/+ buffers/cache: 6279420 43174552 Swap: 50331604 0 50331604 kalyke (Linux)$
Regards
mg.
On Monday 07 December 2009, Diederick Stoffers wrote:
Hi,
We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux).
Hmm.. maybe this has to do with the Xen kernel. Redhat says x86_64 should do 256G/1T (AMD/Intel) and we're successfully running 72G on Centos-5.4.
/Peter
I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Many Thanks,
Diederick
On Mon, Dec 07, 2009 at 01:05:04PM +0100, Diederick Stoffers wrote:
Hi, We have a new 24-core Dell PowerEdge R905 server with 128GB's RAM. The 64 bits version of Fedora 12 lists the correct amount of 128GB, CentOS only finds 32GB (and so does Scientific Linux). I would much prefer to use CentOS (most of the software we use is specifically designed for CentOS). Does anyone know what is causing this/how to fix it?
Have you checked "xm info" to see the Xen hypervisor memory info? Maybe it's just the dom0 linux kernel that doesn't have more than 32G, and the Xen hypervisor sees all of it.
Anyways, you should always limit dom0 memory to 512 MB or 1 GB to disable Xen memory ballooning.
If you boot dom0 with all the (32G of) memory visible to it, and then create VMs, and thus balloon dom0 down to much smaller amount of memory, you'll get all kinds of problems when the dom0 linux memory suddenly is much smaller than it was during boot time.
You should always limit and dedicate some amount of memory to dom0. Use dom0_mem=1G option for xen.gz in grub.conf.
-- Pasi
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Diederick Stoffers -
Jake -
Lucian ＠ lastdot.org -
Marcelo M. Garcia -
Nickolay Bunev -
Pasi Kärkkäinen -
Peter Kjellstrom -
Rudi Ahlers -
Thomas Harold