Bug 1722734
| Summary: | 'qemu-img convert' images over RBD is very very slow | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux Advanced Virtualization | Reporter: | Tingting Mao <timao> |
| Component: | qemu-kvm | Assignee: | Virtualization Maintenance <virt-maint> |
| qemu-kvm sub component: | Ceph | QA Contact: | zixchen |
| Status: | CLOSED WONTFIX | Docs Contact: | |
| Severity: | medium | ||
| Priority: | medium | CC: | coli, jinzhao, juzhang, ngu, qzhang, sgarzare, virt-maint, zhenyzha |
| Version: | 8.0 | Keywords: | Triaged |
| Target Milestone: | rc | Flags: | pm-rhel:
mirror+
|
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2021-03-15 07:36:55 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: | |||
QEMU has been recently split into sub-components and as a one-time operation to avoid breakage of tools, we are setting the QEMU sub-component of this BZ to "General". Please review and change the sub-component if necessary the next time you review this BZ. Thanks After evaluating this issue, there are no plans to address it further or fix it in an upcoming release. Therefore, it is being closed. If plans change such that this issue will be fixed in an upcoming release, then the bug can be reopened. Based on bug 1744525 discussion, rbd with qcow2 is not recommended, so QE agrees to close this bug for now. |
Description of problem: Covert images over RBD is very slow, the consumed time is almost 73 times compared to the time in local. Version-Release number of selected component (if applicable): qemu-kvm-4.0.0-4.module+el8.1.0+3356+cda7f1ee kernel-4.18.0-100.el8.x86_64 How reproducible: 100% Steps to Reproduce: 1. Check the source image info # qemu-img info tgt.qcow2 image: tgt.qcow2 file format: qcow2 virtual size: 20G (21474836480 bytes) disk size: 5.4G cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false 2.Convert to target image in local # time qemu-img convert -f qcow2 -O raw tgt.qcow2 target.img -p (100.00/100%) real 0m5.008s ----------------- Fast! user 0m0.665s sys 0m7.229s 3. Covert to target image over RBD # time qemu-img convert -f qcow2 -O raw tgt.qcow2 rbd:kvmtest-pool/tgt.img -p (100.00/100%) real 6m6.204s ----------------- Slow! user 0m13.993s sys 0m4.553s Actual results: As above. Expected results: The speed for convert images over RBD faster. Additional info: