Description of problem: as subject, this is error message in monitor. (qemu) qemu-kvm: block-qcow2.c:1621: qcow_aio_write_cb: Assertion `(acb->cluster_offset & 511) == 0' failed. Aborted (core dumped) backtrace file is in attachment. Version-Release number of selected component (if applicable): host info: # uname -r 2.6.18-268.el5 #rpm -qa|grep kvm kvm-83-237.el5 guest info: RHEL6.1_64 How reproducible: Steps to Reproduce: 1./usr/libexec/qemu-kvm -M rhel5.6.0 -m 4096 -smp 4,sockets=4,cores=1,threads=1 -name RHEL5u7 -uuid 13bd47ff-7458-a214-9c43-d311ed5ca5a3 -monitor stdio -no-kvm-pit-reinjection -boot c -drive file=/dev/vg0/data1,if=virtio,format=qcow2,cache=none,boot=on,werror=stop -net nic,macaddr=54:52:00:52:ed:62,vlan=0,model=e1000 -net tap,script=/etc/qemu-ifup,downscript=no,vlan=0 -vnc :1 -balloon none -notify all -no-hpet -soundhw ac97 2.run below script in guest for ((;;)) do dd if=/dev/zero of=test1 bs=1M count=10000 done 3. after several minutes, monitor will show below core dumped message. (qemu) qemu-kvm: block-qcow2.c:1621: qcow_aio_write_cb: Assertion `(acb->cluster_offset & 511) == 0' failed. Aborted (core dumped) Actual results: core dumped Expected results: guest work well Additional info: kvm storage: block device(iscsi)
repeat 3 times for above steps, 100% reproduce.
Created attachment 505964 [details] backtrace
since only LV(/dev/vg0/data1) can reproduce this issue. in order to reproduce this bug i did below two testing: 1. i reinstall guest on LV(/dev/vg0/data1) and run dd command in guest 2. use other LV to start vm and run dd command in guest but all can not reproduce this bug, i am not sure how to trigger it.
Can you please try qemu-img check on this image? Do you know if there have been I/O errors?
for block device qemu-img don't support check option. # qemu-img check /dev/vg0/data1 qemu-img: This image format does not support checks
Try the -f option: # qemu-img check -f qcow2 /dev/vg0/data1
hi kevin as i suspect guest maybe have problems that lead to core dump, so i reinstalled guest and try to reproduce it on lv data1. but after reinstall guest this bug can not be reproduced. now lv data1 haven't any errors and guest work well. # qemu-img check -f qcow2 /dev/vg0/data1 No errors were found on the image.
There seems to be a real bug somewhere, but it hasn't been reproduced so far and we don't have any useful information about the broken image. Closing.