Bug 1940036
| Summary: | [incremental_backup][migration_with_storage] When migration finished, the bitmap in the source image was not kept | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux Advanced Virtualization | Reporter: | yisun |
| Component: | libvirt | Assignee: | Peter Krempa <pkrempa> |
| Status: | CLOSED WONTFIX | QA Contact: | yisun |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | 8.4 | CC: | fjin, pkrempa, virt-maint, yafu |
| Target Milestone: | rc | Keywords: | Triaged |
| Target Release: | 8.4 | Flags: | pm-rhel:
mirror+
|
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2021-07-26 13:13:20 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: | |||
Bitmaps are deliberately not saved on the source of the migration when the bitmap migration is used. This is a deliberate decision done in qemu so that migration with shared storage can also use this feature. Said that the use case you are showing is uncommon at best as it involves rolling back state of disks. In general users are expected to either migrate back with the changes (and bitmaps) or copy the new images. Solving this would require both work in qemu and libvirt and in general isn't very desired or useful, thus libvirt will not address this. |
Description of problem: [incremental_backup][migration_with_storage] When migration finished, the bitmap in the source image was not kept Version-Release number of selected component (if applicable): libvirt-7.0.0-9.module+el8.4.0+10326+5e50a3b6.x86_64 How reproducible: 100% Steps to Reproduce: 1. start a vm with image has no bitmaps [root@dell-per740-01 ~]# virsh domblklist vm1 Target Source -------------------------------------------------------- vda /var/lib/libvirt/images/jeos-27-x86_64.qcow2 [root@dell-per740-01 ~]# qemu-img info /var/lib/libvirt/images/jeos-27-x86_64.qcow2 image: /var/lib/libvirt/images/jeos-27-x86_64.qcow2 file format: qcow2 virtual size: 10 GiB (10737418240 bytes) disk size: 1 GiB cluster_size: 65536 Format specific information: compat: 1.1 compression type: zlib lazy refcounts: false refcount bits: 16 corrupt: false extended l2: false [root@dell-per740-01 ~]# virsh start vm1 Domain 'vm1' started 2. create a checkpoint for vm's vda [root@dell-per740-01 ~]# virsh checkpoint-create-as vm1 --description test --name ck1 --diskspec vda,checkpoint=bitmap Domain checkpoint ck1 created 3. do migration [root@dell-per740-01 ~]# virsh migrate vm1 --live qemu+ssh://lenovo-sr630-10.lab.eng.pek2.redhat.com/system --verbose --copy-storage-all root.eng.pek2.redhat.com's password: Migration: [100 %] 4. after migration, check the image's info on source host, the bitmap not saved in that image [root@dell-per740-01 ~]# qemu-img info /var/lib/libvirt/images/jeos-27-x86_64.qcow2 image: /var/lib/libvirt/images/jeos-27-x86_64.qcow2 file format: qcow2 virtual size: 10 GiB (10737418240 bytes) disk size: 1 GiB cluster_size: 65536 Format specific information: compat: 1.1 compression type: zlib lazy refcounts: false refcount bits: 16 corrupt: false extended l2: false 5. if we use this vm on source host again, the checkpoint metadata and bitmap in image will be inconsistent [root@dell-per740-01 ~]# virsh start vm1 Domain 'vm1' started [root@dell-per740-01 ~]# virsh checkpoint-list vm1 Name Creation Time ----------------------------------- ck1 2021-03-16 08:20:58 -0400 [root@dell-per740-01 ~]# virsh checkpoint-delete vm1 ck1 error: Failed to delete checkpoint ck1 error: internal error: bitmap 'ck1' not found in backing chain of 'vda' Expected results: The checkpoint(bitmap) on the source host image should be kept.