On Sun, Oct 23, 2011 at 08:54:13PM +0300, Peter Peltonen wrote: > Replying to myself: > > On Sun, Oct 23, 2011 at 5:51 PM, Peter Peltonen > <peter.peltonen at gmail.com> wrote: > > There is something fishy going around... I will now try to yum update > > dom0 and domUs, set the dom0-min-mem to 2048M and reboot and see what > > happens. > > After rebooting I seemed to have 2048M in dom0 regardless of how many > domUs were running. > > But when trying to create the last domU, I was informed that xend was > out of memory. At this time I still had something about 5G of real > memory available for the last domU which I have configured to consume > 4G of memory. > > I tweaked grub.conf and xend-config.sxp and set 4096M as the dom0 > memory and rebooted again. I reduced the domU memory sizes accordingly > and all domUs got created without errors. But the strange thing is > again dom0 memory which has been reduced from 4096M to 2052M: > > [root at si ~]# cat /etc/xen/xend-config.sxp |grep dom0-min-mem > # dom0-min-mem is the lowest permissible memory level (in MB) for dom0. > (dom0-min-mem 4096) > > [root at si ~]# xl info |grep mem > total_memory : 24567 > free_memory : 5853 > xen_commandline : dom0_mem=4096M dom0_max_vcpus=1 dom0_vcpus_pin > > [root at si ~]# xl list > Name ID Mem VCPUs State Time(s) > Domain-0 0 2052 1 r----- 265.6 > > xl top reports "(MEM)k" as "2101272" and "MAXMEM(k)" as "no limit". > > In CentOS5 with Xen3 I have been used to having the amount of memory > in dom0 which I have specified. My Xen4 installation seems not to do > this. > > If someone else is using the Xen4 packages from > http://xenbits.xen.org/people/mayoung/EL6.xen I would be interested in > hearing about your experiences? > Replying to an old thread.. two things: 1) you might need to use "dom0_mem=2048M,max:2048M" parameter for Xen hypervisor to give the maximum upper limit for dom0. 2) (Earlier) there was a bug in the dom0 kernel code where it allocated wrong amount of memory; you had to use "mem=2048M" option for Linux dom0 kernel in addition to the dom0_mem= option for Xen to get the correct amount of memory for dom0. -- Pasi