Red Hat Bugzilla – Bug 681777
floppy I/O error after live migration while floppy in use
Last modified: 2015-11-22 22:34:00 EST
Description of problem: keep write date to floppy ,do live migration during the time .After migration competed ,floppy returns Input/output error Version-Release number of selected component (if applicable): # uname -r 2.6.32-118.el6.x86_64 # rpm -q qemu-kvm qemu-kvm-0.12.1.2-2.148.el6.x86_64 How reproducible: 100% Steps to Reproduce: 1.start VM with floppy disk eg:/usr/libexec/qemu-kvm -enable-kvm -m 4G -smp 4 -name rhel6U1 -uuid adcbfb49-3411-1701-3c36-6bdbc00bedb9 -rtc base=utc,clock=host,driftfix=slew -boot c -drive file=/dev/mike/RHEL6U1_backup,if=none,id=mike_d1,format=qcow2,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,drive=mike_d1,id=mike_d1 -netdev tap,id=hostnet0,vhost=on -device virtio-net-pci,netdev=hostnet0,id=net0,mac=a2:54:50:a4:c2:c1 -chardev pty,id=serial0 -device isa-serial,chardev=serial0 -usb -device usb-tablet,id=input0 -vnc :2 -device virtio-balloon-pci,id=ballooning -monitor stdio -drive file=/mnt/virtio-win_mike.vfd,if=none,id=f1,format=raw,cache=none -global isa-fdc.driveA=f1 2.in the guest ,open the floppy in gnome .Write data on the floppy for((;;)) do echo hello > /media/disk/file rm -rf /media/disk/file echo "good" done 3.do live migration (qemu) migrate -d tcp:t1:5888 Actual results: After migration ,the floppy returns I/O error,can not write date to floppy. #demsg floppy0: disk absent or changed during operation end_request: I/O error, dev fd0, sector 2 floppy0: disk absent or changed during operation end_request: I/O error, dev fd0, sector 16 EXT4-fs error (device fd0): ext4_read_block_bitmap: Cannot read block bitmap - block_group = 0, block_bitmap = 8 EXT4-fs (fd0): previous I/O error to superblock detected floppy0: disk absent or changed during operation end_request: I/O error, dev fd0, sector 2 EXT4-fs (fd0): previous I/O error to superblock detected floppy0: disk absent or changed during operation end_request: I/O error, dev fd0, sector 2 __ratelimit: 2658 callbacks suppressed Buffer I/O error on device fd0, logical block 1 lost page write due to I/O error on fd0 floppy0: disk absent or changed during operation end_request: I/O error, dev fd0, sector 82 Buffer I/O error on device fd0, logical block 41 lost page write due to I/O error on fd0 Expected results: the scripts still works to write data on floppy. Additional info:
Reproduced on qemu-kvm-0.12.1.2-2.135.el6 Verified on qemu-kvm-0.12.1.2-2.158.el6 with the steps on comment #0 Actual Results: After migration,the scripts still works Based on above ,this issue has been fixed ald.
this issue have been fixed on windows2008r2. verify steps and version info: 1. /usr/libexec/qemu-kvm -m 6G -smp 1 -drive file=/mnt/2008r2-des.raw,media=disk,if=none,id=drive-virtio0-0-0,format=raw,werror=stop,rerror=stop,cache=none -device ide-drive,drive=drive-virtio0-0-0,id=virti0-0-0 -netdev tap,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:94:a3:8b -uuid 9e6f04cf-2ad7-45aa-9333-2d2ee26570c6 -boot c -monitor stdio -spice id=on,disable-ticketing,port=5911 -vga qxl -device virtio-balloon-pci,id=balloon1 -drive file=/mnt/virtio-win-1.1.16.vfd,if=none,id=f1,format=raw,cache=none -global isa-fdc.driveA=f1 2.rpm -qa|grep kvm qemu-kvm-0.12.1.2-2.158.el6.x86_64 3. after migration,loop script still can write date on floppy. 4. @echo off :for1 for /l %%i in (1 2 3) do ( echo "test">A:\test1 del A:\test1 ) goto for1
based on comment #12 &comment #13 ,move staus to VERIFIED.
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Cause: the media_changed flag were not save and restored during migration, bug in the floppy migration code. Consequence: Guest driver may always think the floppy drive were changed after migration, so after the migration, the floppy were unusable. Fix: Fix floppy migration code. Result: transfer file to floppy during migration would works well
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2011-0534.html
Hi ,Jason Since we support migration between RHEL6.0.0 host and RHEL6.2.0 host I think we need to backport this patch to rhel6.0.z . What's your opinion ?
Hi Mike: This patch is functionally reverted in 6.1. I don't know the current status of the fixing for this in either RHEL6 or upstream. I think maybe you can ask Kevin or Markus for this. Thanks