Ronney Meier Rorotec GmbH
2011-Jun-07 18:00 UTC
[Xen-users] "maxmem" without "memory" in hvm-domU-config causes dom0 to reboot
I''m using xen with several domUs. I accidentally removed the "memory" parameter from one of my hvm domU configs and only the maxmem parameter stayed left. Then I had to notice that as soon as the domU gets created dom0 reboots directly (about 1-2 seconds after "xm create <domUname>"), without showing a kernel panic or any other kind of message on the screen. It doesn''t depend which os domU needs to boot, I also tried it out with an empty image file. As soon as I added the "memory" parameter again, everything worked fine again. Otherwise my dom0 is working stable with about 3-8 domUs, so I don''t mind too much about this behaviour... Anyway I don''t know if this is a known (or unknown?) bug (I couldn''t find any information about it) or if there''s something wrong with my system, so I''m just asking here if anybody ever had similar problems.. I''m using Debian Squeeze with kernel version 2.6.32-5-xen-amd64, xen version 4.0.1-2 Don''t think that it should matter, but the domU images are stored on a mdadm raid1 with drbd and lvm2 on top. domU config: # -*- mode: python; -*- kernel = "/usr/lib/xen-default/boot/hvmloader" builder =''hvm'' # when commenting out the below memory parameter the system will restart when creating domU #memory = 6144 maxmem = 6144 shadow_memory = 8 name = "windows_sb" vif = [''type=ioemu, bridge=br3''] acpi=1 apic=1 disk [''file:/xendata/windows-sb-2011-64bit.img,xvda,w'',''file:/xendata/iso/win dows-sb-std-2011-64bit.iso,xvdc:cdrom,r''] device_model = ''/usr/lib/xen-default/bin/qemu-dm'' boot="dc" localtime=1 sdl=0 vnc=1 vnclisten="0.0.0.0" vncconsole=1 vncpasswd='':-P'' stdvga=0 serial=''pty'' usbdevice=''tablet'' on_poweroff = ''destroy'' on_reboot = ''restart'' on_crash = ''restart'' ----------------------- xm info: host : xenmaster release : 2.6.32-5-xen-amd64 version : #1 SMP Thu May 19 01:16:47 UTC 2011 machine : x86_64 nr_cpus : 4 nr_nodes : 1 cores_per_socket : 4 threads_per_core : 1 cpu_mhz : 1200 hw_caps : bfebfbff:2c100800:00000000:00001f40:029ee3ff:00000000:00000001:00000000 virt_caps : hvm hvm_directio total_memory : 16320 free_memory : 7861 node_to_cpu : node0:0-3 node_to_memory : node0:7861 node_to_dma32_mem : node0:2173 max_node_id : 0 xen_major : 4 xen_minor : 0 xen_extra : .1 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable xen_commandline : placeholder dom0_mem=512M dom0_max_vcpus=1 dom0_vcpus_pin cc_compiler : gcc version 4.4.5 (Debian 4.4.5-10) cc_compile_by : waldi cc_compile_domain : debian.org cc_compile_date : Wed Jan 12 14:04:06 UTC 2011 xend_config_format : 4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James Dingwall
2011-Jun-08 09:17 UTC
RE: [Xen-users] "maxmem" without "memory" in hvm-domU-config causes dom0 to reboot
> Anyway I don''t know if this is a known (or unknown?) bug (I couldn''t > find any information about it) or if there''s something wrong with my > system, so I''m just asking here if anybody ever had similar problems..I think that this is the known (and expected) behaviour and I had similar issues when I set memory < max_mem for an HVM. My understanding is that Xen is ballooning RAM for the HVM but the HVM doesn''t know how to correctly accept it as there is no balloon driver. At some point the HVM then tries to address RAM between memory and max_mem but as it is not properly configured it crashes. James This message and the information contained herein is proprietary and confidential and subject to the Amdocs policy statement, you may review at http://www.amdocs.com/email_disclaimer.asp _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users