Bug 1568407
Summary: | Guest is left paused on source host sometimes if kill source libvirtd during live migration due to QEMU image locking | ||
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Product: | Red Hat Enterprise Linux 7 | Reporter: | Jiri Denemark <jdenemar> |
Component: | libvirt | Assignee: | Jiri Denemark <jdenemar> |
Status: | CLOSED ERRATA | QA Contact: | Fangge Jin <fjin> |
Severity: | high | Docs Contact: | |
Priority: | medium | ||
Version: | 7.5 | CC: | chayang, coli, dgilbert, dyuan, famz, fjin, hhuang, jdenemar, jinzhao, juzhang, knoel, kwolf, lmen, michen, ngu, pingl, qzhang, virt-bugs, virt-maint, xianwang, xuzhang, yafu, yuhuang |
Target Milestone: | rc | ||
Target Release: | --- | ||
Hardware: | x86_64 | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | libvirt-4.5.0-1.el7 | Doc Type: | If docs needed, set a value |
Doc Text: | Story Points: | --- | |
Clone Of: | 1560854 | Environment: | |
Last Closed: | 2018-10-30 09:53:26 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: | |||
Bug Depends On: | 1560854 | ||
Bug Blocks: |
Description
Jiri Denemark
2018-04-17 12:40:15 UTC
We'll need to enable a new migration capability (late-block-activate) to request delayed activation of block devices. Patch sent upstream for review: https://www.redhat.com/archives/libvir-list/2018-June/msg00228.html Fixed upstream by commit 4370ac84f86e8f2d71a1d1e1cc65f7238359c36e Refs: v4.4.0-89-g4370ac84f8 Author: Jiri Denemark <jdenemar> AuthorDate: Tue Apr 17 14:46:29 2018 +0200 Commit: Jiri Denemark <jdenemar> CommitDate: Tue Jun 5 09:39:24 2018 +0200 qemu: Fix domain resume after failed migration Libvirt relies on being able to kill the destination domain and resume the source one during migration until we called "cont" on the destination. Unfortunately, QEMU automatically activates block devices at the end of migration even when it's called with -S. This wasn't a big issue in the past since the guest is not running and thus no data are written to the block devices. However, when QEMU introduced its internal block device locks, we can no longer resume the source domain once the destination domain already activated the block devices (and thus acquired all locks) unless the destination domain is killed first. Since it's impossible to synchronize the destination and the source libvirt daemons after a failed migration, QEMU introduced a new migration capability called "late-block-activate" which ensures QEMU won't activate block devices until it gets "cont". The only thing we need to do is to enable this capability whenever QEMU supports it. https://bugzilla.redhat.com/show_bug.cgi?id=1568407 QEMU commit implementing the capability: v2.12.0-952-g0f073f44df Signed-off-by: Jiri Denemark <jdenemar> Reviewed-by: Ján Tomko <jtomko> Verified with libvirt-4.5.0-4.el7.x86_64 and qemu-kvm-rhev-2.12.0-8.el7.x86_64. Steps are same as https://bugzilla.redhat.com/show_bug.cgi?id=1560854#c10, except that the breakpoint changed to:qemu/qemu_migration.c:4695 Also did regression test for cross migration, migration succeeds: 7.6<->7.5 7.6<->7.4 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-2018:3113 |