[libvirt] Some problem with the save function

Hi everyone. This is my first post to this list, so excuse me if it's not the right place to poste info like this. I've found some problems in qemu_driver.c in the latest versions of libvirt: - the first problem was also present in 0.7.0. If we run qemu guests unprivileged, we cannot use the save function (virsh save guestname /path/to/file). The reason seems to be that libvirt first create the destination file to write the header and the XML definition. The file is owned by root with 600 permission. Then, we ask qemu to append the dump of the memory (via the migrate exec: call) to this file. This part doesn't work because the qemu user cannot write to this file. So we endup with a file which only contains the header and the XML, and the guest is stoped :/ - the second problem is present since libvirt 0.7.1. Now that the saved file can be compressed, it seems we cannot save in a raw format any more. This is due to this part in the code (qemu_driver.c): if (STREQ (prog, "raw")) prog = "cat"; internalret = virAsprintf(&command, "migrate \"exec:" "%s -c >> '%s' 2>/dev/null\"", prog, safe_path); which result in "migrate \"exec cat -c >> safe_path 2>/dev/null\"" But cat doesn't support the -c argument, so once again, the save fails, as we end up with a save file which only contains the header and the XML definition. Unfortunately, my C knowledge is near 0, so I cannot correct this myself. - the third problem, is that restore doesn't work any more. I haven't dig it yet, but when I try to restore a guest using a saved file (uncompressed produced under libvirt 0.7.0), I've this error: virsh restore /tmp/guest.state error: Failed to restore domain from /tmp/guest.state error: internal error unable to start guest: Nothing interesting in /var/log/libvirt/qemu/guest.log: LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin HOME=/root USER=root LOGNAME=root /usr/bin/qemu-kvm -S -M pc -m 2048 -smp 4 -name guest -uuid 37b5937b-eacf-fda6-f4d0-33537d61b414 -monitor unix:/var/lib/libvirt/qemu/guest.monitor,server,nowait -localtime -no-reboot -boot c -drive file=/dev/data/guest,if=ide,index=0,boot=on -drive file=/var/lib/libvirt/iso/boot.iso,if=ide,media=cdrom,index=2 -net nic,macaddr=52:54:00:48:c4:ca,vlan=0,name=nic.0 -net tap,fd=25,vlan=0,name=tap.0 -serial pty -parallel none -usb -usbdevice tablet -vnc 127.0.0.1:0 -k fr -vga cirrus -incoming exec:cat The qemu process eats 100% of CPU during a few seconds, then stops (if I strace it during this time, I see a lot of error like bad file descriptor). Anyone have save/restore functions working with 0.7.1 ? Cheers, Daniel -- Daniel Berteaud FIREWALL-SERVICES SARL. Société de Services en Logiciels Libres Technopôle Montesquieu 33650 MARTILLAC Tel : 05 56 64 15 32 Fax : 05 56 64 15 32 Mail: daniel(a)firewall-services.com Web : http://www.firewall-services.com