Bug 1446498
| Summary: | Guest freeze after live snapshot with data-plane | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Qianqian Zhu <qizhu> |
| Component: | qemu-kvm-rhev | Assignee: | Stefan Hajnoczi <stefanha> |
| Status: | CLOSED ERRATA | QA Contact: | Qianqian Zhu <qizhu> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 7.4 | CC: | chayang, famz, juzhang, knoel, michen, pbonzini, qizhu, virt-maint, xfu |
| Target Milestone: | rc | Keywords: | Regression |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-rhev-2.9.0-5.el7 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2017-08-02 04:35:59 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Can you collect the backtrace of all threads when it hangs? Stefan managed to reproduce this and we've located the root cause. Backtrace doesn't really help here, the issue is the iothread didn't get awakened correctly by aio_enable_external(). Clearing the needinfo therefore. A fix will need to be worked on upstream. I've posted a patch upstream ("[PATCH] aio: add missing aio_notify() to aio_enable_external()") and will backport it.
Patch posted downstream. Fix included in qemu-kvm-rhev-2.9.0-5.el7 Verified on: qemu-kvm-rhev-2.9.0-5.el7.x86_64 kernel-3.10.0-640.el7.x86_64 Steps same as comment 0, add block stream test afterwards. Result: As expected, guest works well after live snapshot and block stream. Moving to VERIFIED. Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHSA-2017:2392 |
Description of problem: Guest hang after live snapshot with data-plane Version-Release number of selected component (if applicable): qemu-kvm-rhev-2.9.0-1.el7.x86_64 kernel-3.10.0-643.el7.x86_64 How reproducible: 100% Steps to Reproduce: 1. Launch guest with data-plane: /usr/libexec/qemu-kvm \ -name 'avocado-vt-vm1' \ -vga cirrus \ -object iothread,id=iothread0 \ -device virtio-scsi-pci,iothread=iothread0,id=virtio_scsi_pci0,bus=pci.0,addr=03 \ -drive id=drive_image1,if=none,snapshot=off,aio=native,cache=none,format=qcow2,file=/home/kvm_autotest_root/images/rhel74-64-virtio-scsi.qcow2 \ -device scsi-hd,id=image1,drive=drive_image1 \ -device virtio-net-pci,mac=9a:ac:ad:ae:af:b0,id=idqKTtyC,vectors=4,netdev=idBAxKKY,bus=pci.0,addr=04 \ -netdev tap,id=idBAxKKY,vhost=on \ -m 4096 \ -smp 4,cores=2,threads=1,sockets=2 \ -cpu 'SandyBridge',+kvm_pv_unhalt \ -vnc :0 \ -rtc base=utc,clock=host,driftfix=slew \ -boot order=cdn,once=c,menu=off,strict=off \ -monitor stdio \ -qmp tcp::5555,server,nowait 2. Live snapshot: {'execute': 'blockdev-snapshot-sync', 'arguments': {'device': 'drive_image1', 'snapshot-file': '/home/kvm_autotest_root/images/sn1', 'mode': 'absolute-paths', 'format': 'qcow2'}, 'id': 'Wh5neQ4H'} 3. Check guest Actual results: Guest freeze, no response to mouse and keyboard. Tt's able to ping, but can't ssh login. Expected results: Guest works well. Additional info: qemu-kvm-rhev-2.6.0-27.el7.x86_64 works well, so this is a regression.