Re: I/O errors in guest OS after repeated migration

[Brian Jackson <iggy@theiggy.com>]

On Wednesday, October 17, 2012 10:45:14 AM Guido Winkelmann wrote:
> Am Dienstag, 16. Oktober 2012, 12:44:27 schrieb Brian Jackson:
> > On Tuesday, October 16, 2012 11:33:44 AM Guido Winkelmann wrote:
> > > The commandline, as generated by libvirtd, looks like this:
> > > 
> > > LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
> > > QEMU_AUDIO_DRV=none /usr/bin/qemu-kvm -S -M pc-0.15 -enable-kvm -m 1024
> > > -smp 1,sockets=1,cores=1,threads=1 -name migratetest2 -uuid
> > > ddbf11e9-387e-902b-4849-8c3067dc42a2 -nodefconfig -nodefaults -chardev
> > > socket,id=charmonitor,path=/var/lib/libvirt/qemu/migratetest2.monitor,s
> > > erv e
> > > r,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc
> > > -no-reboot -no- shutdown -device
> > > piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive
> > > file=/data/migratetest2_system,if=none,id=drive-virtio-
> > > disk0,format=qcow2,cache=none -device virtio-blk-
> > > pci,scsi=off,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-
> > > disk0,bootindex=1 -drive
> > > file=/data/migratetest2_data-1,if=none,id=drive-
> > > virtio-disk1,format=qcow2,cache=none -device virtio-blk-
> > > pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk1,id=virtio-disk
> > > 1 - netdev tap,fd=27,id=hostnet0,vhost=on,vhostfd=28 -device
> > > virtio-net-
> > > pci,netdev=hostnet0,id=net0,mac=02:00:00:00:00:0c,bus=pci.0,addr=0x3
> > > -vnc 127.0.0.1:2,password -k de -vga cirrus -incoming
> > > tcp:0.0.0.0:49153 -device
> > > virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6
> > 
> > I see qcow2 in there. Live migration of qcow2 was a new feature in 1.0.
> > Have you tried other formats or different qemu/kvm versions?
> 
> I tried the same thing with a raw image file instead of qcow2, and the
> problem still happens. From the /var/log/messages of the guest:
> 
> Oct 17 17:10:34 localhost sshd[2368]: nss_ldap: could not search LDAP
> server - Server is unavailable
> Oct 17 17:10:39 localhost kernel: [  126.800075] eth0: no IPv6 routers
> present Oct 17 17:10:52 localhost kernel: [  140.335783] Clocksource tsc
> unstable (delta = -70265501 ns)
> Oct 17 17:12:04 localhost /O error on device vda1, logical block 1858765
> Oct 17 17:12:04 localhost kernel: [  212.070584] Buffer I/O error on device
> vda1, logical block 1858766
> Oct 17 17:12:04 localhost kernel: [  212.070587] Buffer I/O error on device
> vda1, logical block 1858767
> Oct 17 17:12:04 localhost kernel: [  212.070589] Buffer I/O error on device
> vda1, logical block 1858768
> Oct 17 17:12:04 localhost kernel: [  212.070592] Buffer I/O error on device
> vda1, logical block 1858769
> Oct 17 17:12:04 localhost kernel: [  212.070595] Buffer I/O error on device
> vda1, logical block 1858770
> Oct 17 17:12:04 localhost kernel: [  212.070597] Buffer I/O error on device
> vda1, logical block 1858771
> Oct 17 17:12:04 localhost kernel: [  212.070600] Buffer I/O error on device
> vda1, logical block 1858772
> Oct 17 17:12:04 localhost kernel: [  212.070602] Buffer I/O error on device
> vda1, logical block 1858773
> Oct 17 17:12:04 localhost kernel: [  212.070605] Buffer I/O error on device
> vda1, logical block 1858774
> Oct 17 17:12:04 localhost kernel: [  212.070607] Buffer I/O error on device
> vda1, logical block 1858775
> Oct 17 17:12:04 localhost kernel: [  212.070610] Buffer I/O error on device
> vda1, logical block 1858776
> Oct 17 17:12:04 localhost kernel: [  212.070612] Buffer I/O error on device
> vda1, logical block 1858777
> Oct 17 17:12:04 localhost kernel: [  212.070615] Buffer I/O error on device
> vda1, logical block 1858778
> Oct 17 17:12:04 localhost kernel: [  212.070617] Buffer I/O error on device
> vda1, logical block 1858779
> 
> (I was writing a large file at the time, to make sure I actually catch I/O
> errors as they happen)


What about newer versions of qemu/kvm? But of course if those work, your next 
task is going to be git bisect it or file a bug with your distro that is using 
an ancient version of qemu/kvm.


> 
> 	Guido
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html