Hi, I'm experiencing I/O errors in a guest machine after migrating it from one host to another, and then back to the original host. After doing this, I find the following in the dmesg output of the guest machine: [ 345.390543] end_request: I/O error, dev vda, sector 273871 [ 345.391125] end_request: I/O error, dev vda, sector 273871 [ 345.391705] end_request: I/O error, dev vda, sector 273871 [ 345.394796] end_request: I/O error, dev vda, sector 1745983 [ 345.396005] end_request: I/O error, dev vda, sector 1745983 [ 346.083160] end_request: I/O error, dev vdb, sector 54528008 [ 346.083179] Buffer I/O error on device dm-0, logical block 6815745 [ 346.083181] lost page write due to I/O error on dm-0 [ 346.083193] end_request: I/O error, dev vdb, sector 54528264 [ 346.083195] Buffer I/O error on device dm-0, logical block 6815777 [ 346.083197] lost page write due to I/O error on dm-0 [ 346.083201] end_request: I/O error, dev vdb, sector 2056 [ 346.083204] Buffer I/O error on device dm-0, logical block 1 [ 346.083206] lost page write due to I/O error on dm-0 [ 346.083209] Buffer I/O error on device dm-0, logical block 2 [ 346.083211] lost page write due to I/O error on dm-0 [ 346.083215] end_request: I/O error, dev vdb, sector 10248 [ 346.083217] Buffer I/O error on device dm-0, logical block 1025 [ 346.083219] lost page write due to I/O error on dm-0 [ 346.091499] end_request: I/O error, dev vdb, sector 76240 [ 346.091506] Buffer I/O error on device dm-0, logical block 9274 [ 346.091508] lost page write due to I/O error on dm-0 [ 346.091572] JBD2: Detected IO errors while flushing file data on dm-0-8 [ 346.091915] end_request: I/O error, dev vdb, sector 38017360 [ 346.091956] Aborting journal on device dm-0-8. [ 346.092557] end_request: I/O error, dev vdb, sector 38012928 [ 346.092566] Buffer I/O error on device dm-0, logical block 4751360 [ 346.092569] lost page write due to I/O error on dm-0 [ 346.092624] JBD2: I/O error detected when updating journal superblock for dm-0-8. [ 346.100940] end_request: I/O error, dev vdb, sector 2048 [ 346.100948] Buffer I/O error on device dm-0, logical block 0 [ 346.100952] lost page write due to I/O error on dm-0 [ 346.101027] EXT4-fs error (device dm-0): ext4_journal_start_sb:327: Detected aborted journal [ 346.101038] EXT4-fs (dm-0): Remounting filesystem read-only [ 346.101051] EXT4-fs (dm-0): previous I/O error to superblock detected [ 346.101836] end_request: I/O error, dev vdb, sector 2048 [ 346.101845] Buffer I/O error on device dm-0, logical block 0 [ 346.101849] lost page write due to I/O error on dm-0 [ 373.006680] end_request: I/O error, dev vda, sector 624319 [ 373.007543] end_request: I/O error, dev vda, sector 624319 [ 373.008327] end_request: I/O error, dev vda, sector 624319 [ 374.886674] end_request: I/O error, dev vda, sector 624319 [ 374.887563] end_request: I/O error, dev vda, sector 624319 The hosts are both running Fedora 17 with qemu-kvm-1.0.1-1.fc17.x86_64. The guest machine has been started and migrated using libvirt (0.9.11). Kernel version is 3.5.6-1.fc17.x86_64 on the first host and 3.5.5-2.fc17.x86_64 on the second. The guest machine is on Kernel 3.3.8 and uses ext4 on its disks. 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,server,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-disk1 - 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 The second host has an ext4 filesystem mounted under /data, which it exports using NFSv3 over TCP to the first host, which also mounts it under /data. So far, the problem seems reproducible: When I start another guest machine and do the same thing with it, the same problem happens. Can anybody help me with this problem? Guido -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
