Bitmap Extra data is not supported

Bug #1808928 reported by Ali Sag on 2018-12-18
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
QEMU
Undecided
Unassigned

Bug Description

i am using dirty bitmaps and drive-backup. It works as aspected.

Lately, i encounter a disastrous error. There is not any information about that situation. I cannot reach/open/attach/info or anything with a qcow2 file.

virsh version
Compiled against library: libvirt 4.10.0
Using library: libvirt 4.10.0
Using API: QEMU 4.10.0
Running hypervisor: QEMU 2.12.0

"qemu-img: Could not open '/var/lib/libvirt/images/test.qcow2': Bitmap extra data is not supported"

what is that mean? what should i do?
i cannot remove bitmap. i cannot open image or query.

John Snow (jnsnow) wrote :

Hi, bitmap extensions have a field that allows us to attach extra/arbitrary data to them. It is not currently used by QEMU. If this field is set, it means something corrupted your qcow2.

Please make a backup of your qcow2 file first (because attempting to repair a broken qcow2 can sometimes make it worse), and then please try running qemu-img check to try and diagnose the image.

What happened to cause the "disastrous error", do you recall?

Ali Sag (catborise) wrote :

as far as i know nothing happened. it had worked normally while instance was running. For a reason, instance is shutdown, then it never open again. i have some backups, i tried to return previous backups. But they also gave same error. Thanks to replication i could get it back. i copied image from replication site...

as i said "qemu-img" command completely unusable on that image.
There should be another mechanism. It blocks everything.
I try to edit header to remove extra data. But i could not find header information on website.

thanks

John Snow (jnsnow) wrote :

OK, I think it is a bug that you cannot at least repair the image, though the cause of corruption is still unknown to me. Do you have libvirt/QEMU logs from when then VM was shut down, before it wouldn't boot properly again?

Ali Sag (catborise) wrote :

Sorry, because of log time, VM logs were removed. Journalctl for libvirtd is remain.. It was like that.
018-12-17 17:01:50.990+0000: 43198: error : qemuMonitorIORead:606 : Unable to read from monitor: Connection reset by peer
Dec 17 20:01:50 vm-kvm09 libvirtd[43198]: 2018-12-17 17:01:50.991+0000: 43198: error : qemuProcessReportLogError:1935 : internal error: qemu unexpectedly closed the monitor: .guest_agent.0 -chardev spicevmc,id=charchannel1,name=vdagent -device virtserialport,bus=virtio
Dec 17 20:01:51 vm-kvm09 libvirtd[43198]: 2018-12-17T17:01:50.984315Z qemu-kvm: -drive file=/var/lib/libvirt/images/exo1-jb-h01-2.qcow2,format=qcow2,if=none,id=drive-virtio-disk1,cache=none: Bitmap extra data is not supported
Dec 17 20:02:02 vm-kvm09 libvirtd[43198]: 2018-12-17 17:02:02.652+0000: 43203: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:02:02 vm-kvm09 libvirtd[43198]: 2018-12-17 17:02:02.668+0000: 68990: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:02:02 vm-kvm09 libvirtd[43198]: 2018-12-17 17:02:02.683+0000: 17099: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:09:58 vm-kvm09 libvirtd[43198]: 2018-12-17 17:09:58.700+0000: 68889: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:09:58 vm-kvm09 libvirtd[43198]: 2018-12-17 17:09:58.717+0000: 43200: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:09:58 vm-kvm09 libvirtd[43198]: 2018-12-17 17:09:58.732+0000: 43202: warning : virQEMUCapsInit:923 : Failed to get host CPU cache info
Dec 17 20:09:59 vm-kvm09 libvirtd[43198]: 2018-12-17 17:09:59.144+0000: 43198: error : qemuMonitorIORead:606 : Unable to read from monitor: Connection reset by peer
Dec 17 20:09:59 vm-kvm09 libvirtd[43198]: 2018-12-17 17:09:59.145+0000: 43198: error : qemuProcessReportLogError:1935 : internal error: qemu unexpectedly closed the monitor: 2018-12-17T17:09:59.132340Z qemu-kvm: -drive file=/var/lib/libvirt/images/exo1-jb-h01-2.qcow2,f...

I keep the broken image file. I run some qemu-img commands:

> qemu-img check /var/lib/libvirt/images/exo1-jb-h01-2.qcow2.1712
qemu-img: Could not open '/var/lib/libvirt/images/exo1-jb-h01-2.qcow2.1712': Bitmap extra data is not supported

> qemu-img info /var/lib/libvirt/images/exo1-jb-h01-2.qcow2.1712
qemu-img: Could not open '/var/lib/libvirt/images/exo1-jb-h01-2.qcow2.1712': Bitmap extra data is not supported

To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers