Bug 2025769
| Summary: | virt-v2v fails with the error: Backing file specified without backing format | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Vera <vwu> | ||||
| Component: | virt-v2v | Assignee: | Richard W.M. Jones <rjones> | ||||
| Status: | CLOSED ERRATA | QA Contact: | Vera <vwu> | ||||
| Severity: | high | Docs Contact: | |||||
| Priority: | high | ||||||
| Version: | 8.6 | CC: | chhu, hongzliu, jsuchane, juzhou, mxie, tyan, tzheng, xiaodwan | ||||
| Target Milestone: | rc | ||||||
| Target Release: | --- | ||||||
| Hardware: | Unspecified | ||||||
| OS: | Linux | ||||||
| Whiteboard: | |||||||
| Fixed In Version: | virt-v2v-1.42.0-18.el8 | Doc Type: | If docs needed, set a value | ||||
| Doc Text: | Story Points: | --- | |||||
| Clone Of: | Environment: | ||||||
| Last Closed: | 2022-05-10 13:24:19 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: | |||||||
| Bug Blocks: | 2026666 | ||||||
| Attachments: |
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Upstream fix: https://github.com/libguestfs/virt-v2v/commit/40cfe6da0861ca6360f670e254c71ed923a0402f I've only done the fix upstream in 1.44 because: - Upstream (modular) virt-v2v 2.0 uses qemu-nbd -s (snapshot) option which appears to take care of this. - This is easy to backport to 1.42 for RHEL 8.6. Copying the comment https://bugzilla.redhat.com/show_bug.cgi?id=2026199#c5 over here, so it's not get lost. Please set the status of this bug appropriately if you want to re-use it. From the comment 5 of the bug 2026199: I don't think this is a libvirt bug actually. In the code we don't expect libvirt to return a type here, and so we substitute "raw" format always: https://github.com/libguestfs/virt-v2v/blob/a3d09f8a7435270e376a53d241ee54c2ebab2b0d/v2v/input_libvirt_vcenter_https.ml#L95 However before we reach this code, we go through parse_libvirt_domain here which gives the error about the missing type/format: https://github.com/libguestfs/virt-v2v/blob/a3d09f8a7435270e376a53d241ee54c2ebab2b0d/v2v/parse_libvirt_xml.ml#L270 So this needs another fix in virt-v2v 1.44. I think we can keep the same bug (bug 2025769) for the extra fix. Additional fix required for RHEL 8.6: https://github.com/libguestfs/virt-v2v/commit/59dc3293a9b4fdf11da8571c50e3e5badbb511c2 I checked that this bug does not affect upstream (modular) virt-v2v because we don't use the qcow2 + backing file overlay. Verified with the following version:
virt-v2v-1.42.0-18.module+el8.6.0+13447+4b5d0856.x86_64
libguestfs-1.44.0-4.module+el8.6.0+12969+f61072d9.x86_64
qemu-kvm-6.1.0-5.module+el8.6.0+13430+8fdd5f85.x86_64
Steps to verify:
1. create pool and setup passwordless ssh with xen
2. Convert the vm on xen to libvirt
# virt-v2v -ic xen+ssh://root.224.33/ -o libvirt -of raw -os v2v_dir --mac 00:16:3e:05:de:21:network:v2v_net_0 xen-hvm-rhel7.9-x86_64
[ 0.0] Opening the source -i libvirt -ic xen+ssh://root.224.33/ xen-hvm-rhel7.9-x86_64
[ 1.6] Creating an overlay to protect the source from being modified
[ 2.1] Opening the overlay
[ 8.7] Inspecting the overlay
[ 24.3] Checking for sufficient free disk space in the guest
[ 24.3] Estimating space required on target for each disk
[ 24.3] Converting Red Hat Enterprise Linux Server 7.9 (Maipo) to run on KVM
virt-v2v: This guest has virtio drivers installed.
[ 173.2] Mapping filesystem data to avoid copying unused and blank areas
[ 174.0] Closing the overlay
[ 174.0] Assigning disks to buses
[ 174.0] Checking if the guest needs BIOS or UEFI to boot
[ 174.0] Initializing the target -o libvirt -os v2v_dir
[ 174.6] Copying disk 1/1 to /var/lib/libvirt/images/v2v_pool/xen-hvm-rhel7.9-x86_64-sda (raw)
(100.00/100%)
[ 540.0] Creating output metadata
[ 540.1] Finishing off
# virsh list --all
Id Name State
-----------------------------------------
- xen-hvm-rhel7.9-x86_64 shut off
The conversion is successful.
Moving the bug to the status: 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 (Moderate: virt:rhel and virt-devel:rhel security, bug fix, and enhancement update), 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-2022:1759 |
Created attachment 1843094 [details] debugging log Description of problem: virt-v2v fails with the error: Backing file specified without backing format Version-Release number of selected component (if applicable): virt-v2v-1.42.0-16.module+el8.6.0+13085+a15475d8.x86_64 libguestfs-1.44.0-4.module+el8.6.0+12969+f61072d9.x86_64 qemu-kvm-6.1.0-4.module+el8.6.0+13039+4b81a1dc.x86_64 How reproducible: 100% Steps to Reproduce: 1.Preapre RHEL8.6 conversion server and xen VM 2.Convert VM using virt-v2v: # virt-v2v -ic xen+ssh://root.224.33/ -o libvirt -of raw -os v2v_dir --mac 00:16:3e:05:de:21:network:v2v_net_0 xen-hvm-rhel7.9-x86_64 [ 0.0] Opening the source -i libvirt -ic xen+ssh://root.224.33/ xen-hvm-rhel7.9-x86_64 [ 1.5] Creating an overlay to protect the source from being modified qemu-img: /var/tmp/v2vovlcec68f.qcow2: Backing file specified without backing format Detected format of raw.virt-v2v: error: qemu-img command failed, see earlier errors If reporting bugs, run virt-v2v with debugging enabled and include the complete output: virt-v2v -v -x [...] # Actual results: As above Expected results: The conversion should be sucessful. Additional info: The debugging log is in the attachment