Hi, On Sat, Oct 22, 2011 at 4:21 PM, Pasi Kärkkäinen <pasik at iki.fi> wrote: >> >> and in xend-config.sxp I have: >> >> (dom0-min-mem 256) >> (enable-dom0-ballooning no) >> (total_available_memory 0) >> >> Now one would think that I should have 2048M memory for dom0, right? I >> started from there, but when starting domUs it has been reduced to >> 1140M even though I think ballooning is disabled and there is free >> memory available? And the weird thing is that dom0 has done some >> swapping: >> > > Did you check the amount of memory in dom0 right after boot? > You *might* need to add also "mem=2028M" cmdline option for dom0 linux kernel (vmlinuz). Thanks for the tip! I also googled a tip to set dom0-min-mem to the same amount. I will try this next. >> >> Shutting down domUs and making more memory available does not reverse >> the effect, dom0 does not allocate more memory. >> > > dom0 is not supposed to allocate more memory! > dom0 is a virtual machine. Free memory goes into Xen hypervisor, check with "xl info" or "xm info". I am aware that dom0 is a virtual machine. As I reported earlier, xl info shows: >> total_memory : 24567 >> free_memory : 3698 >> xen_commandline : dom0_mem=2048M There is free memory. Dom0 is supposed to have 2048M memory. Why is it I have only 1140M memory in use with dom0? When I first booted the machine I used to have 2048M memory and then Xen started reducing the memory when I started more domUs. So my problem is: Why is Xen reducing the amount of memory in dom0, even I have disabled ballooning and there is more than enough memory available for the dom0 and domUs? Just a moment ago I experienced the following: I shut down a domU having 4096M memory. Then I tried to start it again and Xen complained that there is no memory available. The second restart produced the following error: libxl: error: libxl_dom.c:168:libxl__build_pv xc_dom_kernel_file failed: Bad address cannot (re-)build domain: -3 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. Best regards, Peter