On 08/04/2016 07:59 AM, Jonatan Schlag wrote:


Am Do, 4. Aug, 2016 um 1:38 schrieb Michal Privoznik <mprivozn@redhat.com>:
On 04.08.2016 12:12, Jonatan Schlag wrote:
Am Do, 4. Aug, 2016 um 11:32 schrieb Michal Privoznik <mprivozn@redhat.com>:
On 03.08.2016 21:17, Jonatan Schlag wrote:
Hi, I have a very strange problem with libvirt. I work on some machines with libvirt (Debian/ Arch Linux) and libvirt set the ownership of images file automatically to the qemu user / group for example on Arch Linux to nobody:kvm. So when I copy an image file with root and use I then with qemu, libvirt change the owner/ group to nobody:kvm. But I also compiled libvirt for a machine (gcc 4.9.4 glibc 2.12) and on this machine libvirt did not change the ownership of the image files which results in this error: libvirtError: internal error: process exited while connecting to monitor: able-ticketing,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,bus=pci.0,addr=0x2 -device intel-hda,id=sound0,bus=pci.0,addr=0x4 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x7 -msg timestamp=on 2016-08-03T18:19:47.494512Z qemu-system-x86_64: -drive file=/data/hdd1/libvirt/images/test.img,format=raw,if=none,id=drive-virtio-disk0: Could not open '/data/hdd1/libvirt/images/test.img': Permission denied
Can you please share the debug logs? http://wiki.libvirt.org/page/DebugLogs Also, my initial suspect, before diving any deeper is that usually, when users compile libvirt on their own, they forget to set the correct prefix, therefore libvirt is looking for its config files NOT under /etc/libvirt but /usr/local/etc/ or whatever. BTW: is the daemon running under root? Michal
Hi, The daemon runs under root. I uploaded the debug logs to: http://people.ipfire.org/~jschlag/1363864/1_libvirtd.log The UID of the user nobody is 99, the GID of the group kvm is 1011. I added my configure options to the bug report. Following the log the ownership is changed but why is the file still owned by root:root?
Right. the file is set ownership.
But the file ist still owned by root:root and so it is not accessable by qemu as nobody:kvm. In the moment the only possible way is that the change of the ownership fail, but then there should be an error message, but there is no error message in the log.

Are you checking it after the operation has failed and libvirt has continued? If libvirt fails to access the file, it will then set everything back to its original state, so looking at the file ownership after the fact tells you nothing. If you really want to see if the file has the proper ownership, you need to attach gdb to libvirtd and set an appropriate breakpoint.