[libvirt] Re: libvirt-0.9.1 to 0.9.3-r1: managedsave/save won't start/restore at saved state

[Nicolas Sebrecht]

The 27/07/11, Eric Blake wrote:
> On 07/27/2011 02:37 AM, Nicolas Sebrecht wrote:
> >I'm seeing strange behaviour, here.  Any guests saved using both
> >managedsave and save commands from virsh won't restore at saved state. A
> >new full boot sequence happen.
> >
> >- Tested against libvirt v0.9.1, v0.9.2, v0.9.3-r1 (Gentoo)
> >- Confirmed on three different hosts Gentoo amd64 systems.
> >- Tested with gentoo and ubuntu guests.
> >- Nothing relevant in /var/log/libvirt/libvirt.log or
> >/var/log/libvirt/qemu/<dom>.log
> >
> >The "state file" /var/lib/libvirt/qemu/save/<dom>.save exists and is
> >deleted when 'virsh start' is called.
> >
> >The new boot sequence is confirmed by :
> >- VNC console checks
> >- previous screen sessions lost
> >- uptime
> >
> >I've open a bug at https://bugs.gentoo.org/show_bug.cgi?id=376333 but
> >had no answer.
> >
> >Any idea on what could happen or how to inspect it?
> 
> Does /var/log/libvirt/qemu/<dom>.log show the qemu process getting
> started with the -incoming fd:nnn flag?  While you claim that
> nothing appeared to be relevant in that log, it might actually help
> to post a few lines of it for confirmation.

Here is a fresh test. Hostnames are:

  nicolas-desktop: my desktop
  homer: guest (logged as root)
  xenon: host (logged as root)


nicolas at nicolas-desktop> ssh homer.test.lan
root at homer> uptime
 10:06:44 up 3 min,  1 user,  load average: 0.10, 0.24, 0.11
root at homer> exit

nicolas at nicolas-desktop> ssh xenon.test.lan
xenon ~ # virsh managedsave homer
Domain homer state saved by libvirt

xenon ~ # cd /var/lib/libvirt/qemu/save
xenon save # ls -l
total 195M
-rw------- 1 root root 195M Jul 28 10:08 homer.save

<waiting a bit>

xenon save # virsh start homer
Domain homer started

xenon save # ls -l
total 0
xenon save # exit
nicolas at nicolas-desktop> ssh homer.test.lan
root at homer> uptime
 10:22:42 up 0 min,  1 user,  load average: 0.00, 0.00, 0.00
root at homer>


nicolas at nicolas-desktop> ssh xenon.test.lan
xenon ~ # tail /var/log/libvirt/qemu/homer.log
2011-07-28 10:03:07.718: shutting down
2011-07-28 10:03:41.103: starting up
LC_ALL=C PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.4.5:/root/bin HOME=/root USER=root QEMU_AUDIO_DRV=none /usr/bin/qemu-kvm -S -M pc-0.11 -enable-kvm -m 512 -smp 2,sockets=2,cores=1,threads=1 -name homer -uuid 90b87fd0-6add-c7c8-e6f8-b8245bae8329 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/homer.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -drive file=/home/piing/libvirt/images/piing/homer.img,if=none,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,bus=pci.0,multifunction=on,addr=0x5.0x0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -drive file=/root/virtuals/images/piing/homer-lun0.raw,if=none,id=drive-virtio-disk1,format=raw -device virtio-blk-pci,bus=pci.0,multifunction=on,addr=0x8.0x0,drive=drive-virtio-disk1,id=virtio-disk1 -drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -netdev tap,fd=17,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:c3:7b:da,bus=pci.0,multifunction=on,addr=0x4.0x0 -netdev tap,fd=18,id=hostnet1 -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:30:15:24,bus=pci.0,multifunction=on,addr=0x3.0x0 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:0 -vga cirrus -incoming fd:13 -device virtio-balloon-pci,id=balloon0,bus=pci.0,multifunction=on,addr=0x6.0x0
Domain id=19 is tainted: high-privileges
char device redirected to /dev/pts/4
2011-07-28 10:08:11.024: shutting down
2011-07-28 10:22:48.203: starting up
LC_ALL=C PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.4.5:/root/bin HOME=/root USER=root QEMU_AUDIO_DRV=none /usr/bin/qemu-kvm -S -M pc-0.11 -enable-kvm -m 512 -smp 2,sockets=2,cores=1,threads=1 -name homer -uuid 90b87fd0-6add-c7c8-e6f8-b8245bae8329 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/homer.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-shutdown -drive file=/home/piing/libvirt/images/piing/homer.img,if=none,id=drive-virtio-disk0,format=qcow2 -device virtio-blk-pci,bus=pci.0,multifunction=on,addr=0x5.0x0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 -drive file=/root/virtuals/images/piing/homer-lun0.raw,if=none,id=drive-virtio-disk1,format=raw -device virtio-blk-pci,bus=pci.0,multifunction=on,addr=0x8.0x0,drive=drive-virtio-disk1,id=virtio-disk1 -drive if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -netdev tap,fd=18,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:c3:7b:da,bus=pci.0,multifunction=on,addr=0x4.0x0 -netdev tap,fd=20,id=hostnet1 -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:30:15:24,bus=pci.0,multifunction=on,addr=0x3.0x0 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:0 -vga cirrus -incoming fd:15 -device virtio-balloon-pci,id=balloon0,bus=pci.0,multifunction=on,addr=0x6.0x0
Domain id=20 is tainted: high-privileges
char device redirected to /dev/pts/5
xenon ~ #


> It's working for me with libvirt 0.9.3 on RHEL 6, so I'm not sure
> what to suggest that you try next.

Yes, I'm pretty sure it works almost always for everybody out there. I suspect
this issue to be somewhat subtle.

Thanks Eric for your help.

-- 
Nicolas Sebrecht