Bug 1406981
| Summary: | guestfish failed to launch nbd qcow2 image with --format=qcow2 | ||||||
|---|---|---|---|---|---|---|---|
| Product: | Red Hat Enterprise Linux 7 | Reporter: | Xianghua Chen <xchen> | ||||
| Component: | libguestfs | Assignee: | Richard W.M. Jones <rjones> | ||||
| Status: | CLOSED NOTABUG | QA Contact: | Virtualization Bugs <virt-bugs> | ||||
| Severity: | medium | Docs Contact: | |||||
| Priority: | medium | ||||||
| Version: | 7.4 | CC: | ptoscano, wshi | ||||
| Target Milestone: | rc | ||||||
| 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: | 2016-12-22 11:59:21 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: | |||||||
| Attachments: |
|
||||||
This is correct and not a bug. The qemu-nbd process opens the qcow2 file and serves it as a raw file. On the client side (libguestfs) you therefore have to access it as raw. |
Created attachment 1234583 [details] log.nbd-qcow2 Description of problem: guestfish failed to launch nbd qcow2 image with --format=qcow2 Version-Release number of selected component (if applicable): libguestfs-1.32.7-3.el7.x86_64 How reproducible: 100% Steps: 1. Prepare a nbd server on fedora: 10.66.9.95 # modprobe nbd Prepare a qcow2 guest image： $ qemu-img info RHEL-Server-7.2-64-hvm.qcow2 image: RHEL-Server-7.2-64-hvm.qcow2 file format: qcow2 virtual size: 8.0G (8589934592 bytes) disk size: 2.2G cluster_size: 65536 Format specific information: compat: 1.1 lazy refcounts: false refcount bits: 16 corrupt: false $ qemu-nbd RHEL-Server-7.2-64-hvm.qcow2 -t 2. On rhel7 client： # guestfish -a nbd://10.66.9.95 -i libguestfs: error: could not auto-detect the format when using a non-file protocol. If the format is known, pass the format to libguestfs, eg. using the '--format' option, or via the optional 'format' argument to 'add-drive'. # guestfish --format=qcow2 -a nbd://10.66.9.95 -i -v -x ... ... ibguestfs: error: could not create appliance through libvirt. Try running qemu directly without libvirt using this environment variable: export LIBGUESTFS_BACKEND=direct Original error from libvirt: internal error: process exited while connecting to monitor: 2016-12-21T08:25:14.437395Z qemu-kvm: -drive file=nbd:10.66.9.95:10809,format=qcow2,if=none,id=drive-scsi0-0-0-0,cache=writeback: could not open disk image nbd:10.66.9.95:10809: Image is not in qcow2 format [code=1 int1=-1] libguestfs: clear_socket_create_context: setsockcreatecon failed: NULL: Invalid argument [you can ignore this message if you are not using SELinux + sVirt] libguestfs: trace: launch = -1 (error) If I use --format=raw it'll be ok： # guestfish --format=raw -a nbd://10.66.9.95 -i Please check the -v -x log in attachment. Actual results: The first 2 command in step2 all failed. Expected results: The guestfish with --format=qcow2 or with no --format should all work. The guestfish with --format=raw should not work. Additional info: # qemu-img info nbd://10.66.9.95 image: file format: raw virtual size: 8.0G (8589934592 bytes) disk size: unavailable Seems like qemu's problem？ But libguestfs should detect it without using --format or have other workaround for this.