Bug 1978526
| Summary: | Storage is not copied at all when do vm live migration with --copy-storage-inc | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 9 | Reporter: | Fangge Jin <fjin> | ||||||
| Component: | libvirt | Assignee: | Virtualization Maintenance <virt-maint> | ||||||
| libvirt sub component: | Live Migration | QA Contact: | Virtualization Bugs <virt-bugs> | ||||||
| Status: | CLOSED CURRENTRELEASE | Docs Contact: | |||||||
| Severity: | high | ||||||||
| Priority: | unspecified | CC: | hhan, jdenemar, jsuchane, pkrempa, virt-maint, xuzhang | ||||||
| Version: | 9.0 | Keywords: | Regression, Triaged | ||||||
| Target Milestone: | beta | ||||||||
| Target Release: | --- | ||||||||
| Hardware: | Unspecified | ||||||||
| OS: | Unspecified | ||||||||
| Whiteboard: | |||||||||
| Fixed In Version: | libvirt-7.6.0-1.el9 | Doc Type: | If docs needed, set a value | ||||||
| Doc Text: | Story Points: | --- | |||||||
| Clone Of: | |||||||||
| : | 1978716 (view as bug list) | Environment: | |||||||
| Last Closed: | 2021-12-07 21:57:54 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: | 7.6.0 | ||||||
| Embargoed: | |||||||||
| Bug Depends On: | |||||||||
| Bug Blocks: | 1978716 | ||||||||
| Attachments: |
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Created attachment 1797029 [details]
domain xml
Created attachment 1797066 [details]
The qmp log of src and dest hosts
Reproduced on libvirt-7.4.0-1.el9.x86_64 qemu-kvm-6.0.0-4.el9.x86_64.
See the qmp log files generated by qemu-monitor.stp.
The problem happens because a wrong constant was used in the logic expression which is used to determine whether storage migration needs to take place. The original condition is: bool storageMigration = flags & (VIR_MIGRATE_NON_SHARED_DISK | QEMU_MONITOR_MIGRATE_NON_SHARED_INC); The correct one is: bool storageMigration = flags & (VIR_MIGRATE_NON_SHARED_DISK | VIR_MIGRATE_NON_SHARED_INC); QEMU_MONITOR_MIGRATE_NON_SHARED_INC equals to 0x04 VIR_MIGRATE_NON_SHARED_INC equals to 0x80 Fixed upstream:
commit b249fa78718cd6c21109b385b568ecd3d6a3a8dd
Author: Peter Krempa <pkrempa>
Date: Fri Jul 2 14:17:58 2021 +0200
NEWS: Mention implications of the bug in migration code
Wrong flag use could have user-visible implications. Mention the fix.
Signed-off-by: Peter Krempa <pkrempa>
Reviewed-by: Ján Tomko <jtomko>
commit f58349c9c6d26d98e7c8c195b1160d0c0cfff080
Author: Peter Krempa <pkrempa>
Date: Fri Jul 2 14:17:57 2021 +0200
qemu: migration: Use correct flag constant for enabling storage migration
The 'storageMigration' flag is supposed to be true if storage migration
is requested, which is based on VIR_MIGRATE_NON_SHARED_DISK or
VIR_MIGRATE_NON_SHARED_INC flags. The assignment to the variable used
QEMU_MONITOR_MIGRATE_NON_SHARED_INC (0x04) instead of
VIR_MIGRATE_NON_SHARED_INC (0x80), caused libvirtd to skip the actual
copy of data.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1978526
Fixes: da69f4b2084bff140238e450e264d6036ebef898
Signed-off-by: Peter Krempa <pkrempa>
Reviewed-by: Ján Tomko <jtomko>
v7.5.0-44-gb249fa7871
Test on libvirt v7.5.0-97-g133d05a15e and qemu-6.0.0-1.fc35.x86_64 as comment0. PASS Verified on libvirt-7.6.0-2.el9.x86_64 qemu-kvm-6.0.0-12.el9.x86_64:
1. Prepare a nbd based on an image with OS
2. Create backing file of nbd on both hosts
# qemu-img info /var/lib/libvirt/images/backing.qcow2
image: /var/lib/libvirt/images/backing.qcow2
file format: qcow2
virtual size: 10 GiB (10737418240 bytes)
disk size: 26 MiB
cluster_size: 65536
backing file: json:{"file":{"driver":"nbd","server":{"type":"inet","host":"10.0.150.247","port":"10809"}}}
backing file format: qcow2
Format specific information:
compat: 1.1
compression type: zlib
lazy refcounts: false
refcount bits: 16
corrupt: false
extended l2: false
3. Refresh the storage pool of backing image
4. Start a VM with backing image. Finish migration with --copy-storage-inc
# virsh migrate fedora34 qemu+ssh://root.150.247/system --live --verbose --copy-storage-inc
Migration: [100 %]
5. Login the VM and write some data to the disk
# dd if=/dev/zero of=file bs=10M count=10
10+0 records in
10+0 records out
104857600 bytes (105 MB, 100 MiB) copied, 2.77315 s, 37.8 MB/s
No I/O error.
Covered by RHEL-120247 |
Created attachment 1797017 [details] libvirtd log Description of problem: As subject Version-Release number of selected component (if applicable): qemu-kvm-6.0.0-7.el9.x86_64 libvirt-7.4.0-1.el9.x86_64 How reproducible: 100% Steps to Reproduce: 1. Start a vm with local storage 2. Pre-create the disk image on target host manually # qemu-img create -f qcow2 /var/lib/avocado/data/avocado-vt/images/jeos-27-x86_64.qcow2 10G # qemu-img info /var/lib/avocado/data/avocado-vt/images/jeos-27-x86_64.qcow2 -U image: /var/lib/avocado/data/avocado-vt/images/jeos-27-x86_64.qcow2 file format: qcow2 virtual size: 10 GiB (10737418240 bytes) disk size: 196 KiB cluster_size: 65536 Format specific information: compat: 1.1 compression type: zlib lazy refcounts: false refcount bits: 16 corrupt: false extended l2: false 2. Migrate vm with --copy-storage-inc # virsh migrate avocado-vt-vm1 qemu+ssh://******/system --live --verbose --copy-storage-inc 3. Check the disk image on dest host, found its size is small # qemu-img info /var/lib/avocado/data/avocado-vt/images/jeos-27-x86_64.qcow2 -U image: /var/lib/avocado/data/avocado-vt/images/jeos-27-x86_64.qcow2 file format: qcow2 virtual size: 10 GiB (10737418240 bytes) disk size: 5.01 MiB cluster_size: 65536 Format specific information: compat: 1.1 compression type: zlib lazy refcounts: false refcount bits: 16 corrupt: false extended l2: false 4. Try to login to vm on dest host, failed 5. Check libvirtd.log, can't find blockdev-add Actual results: As description Expected results: Disk should be copied during migration when --copy-storage-inc is used Additional info: Can't reproduce with --copy-storage-all