WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] understanding dom0 usage memory

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] understanding dom0 usage memory
From: Claudinei Matos <claudineimatos@xxxxxxxxxxxxxxxxx>
Date: Fri, 22 Feb 2008 10:40:14 -0300
Delivery-date: Fri, 22 Feb 2008 08:42:03 -0800
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <47BE5698.3020609@xxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <47B5B99D.3090000@xxxxxxxxxxxxxxxxx> <47BE5698.3020609@xxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 2.0.0.9 (X11/20071031)
Stephan Seitz wrote:
Claudinei Matos schrieb:
Hi guys,


My question is if the xen kernel part do try to allocate memory which I can't see on ps/top utils or if I maybe have a problem with my machines setup? Another question is if it's OK to just allocate 128MB to dom0? As I said the only machine with 128MB is a test machine which is not used this much.

The dom0 memory shown by "free" has nothing to do with your physical ram.
By default, dom0 gets all memory which is not used by domU's.
If you're starting domU's your dom0 memory will shrink until dom0_min_mem
(see xm help, man xm ...). The same way your dom0 memory probably balloons
out if you're stopping domU's.
If you want a static ram size at dom0, you need to add dom0_mem, dom0_max_mem
and/or dom0_min_mem parameters to your grub entry (after xenXXX.gz).

I'm already using boot option "dom0_mem" to limit the physical ram usage on all my nodes as well as the xend-config.sxp "dom0_min_mem" parameter with the same value of "dom0_mem" boot option.

I still in doubt about if xen kernel modules are using the free memory but not showing up its use at top and ps commands.

For tests purpose I've realized that none of the xen visible process do care about the domU "life". I can kill some xen process and the domU still running (I did not tested with blktapctrl as I think it can give some problems with domU storage). So I wonder there's some kernel land process (invisible to ps/top) which care about domU and who's probably consuming some free memory. Is there an away to see such a process and/or even look at its memory usage?



Thanks,

Claudinei Matos

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

<Prev in Thread] Current Thread [Next in Thread>