[libvirt-users] Efficient live disk backup with active blockcommit : Failed 'block-commit': Could not reopen file: Permission denied

[Keyur Bhalerao]

Hi ,

Based on the discussion and links referred as mentioned in earlier thread ,
I could able to perform the block commit and other operations
successfully.  Here are the changes required to perform block commit

1. Used Ubuntu 15.04 which has following versions of Libvirt and Qemu

Compiled against library: libvirt 1.2.12
Using library: libvirt 1.2.12
Using API: QEMU 1.2.12
Running hypervisor: QEMU 2.2.0

-- Need to mention here : The Qemu version 2.3 certainly has some issues
regarding the block commit as lowering the version to 2.2 resolved "active
block job" issue.

2. Modified the configuration /etc/libvirt/qemu.conf
   - Had to modify the qemu.conf file which is under /etc/libvirt to
resolve the permission denied error.
   - Added  security_driver="none"
Supportive reference  : https://libvirt.org/drvqemu.html

I have two question regarding this.-

1. Is there any way we can avoid modifying /etc/libvirt/qemu.conf  for
security driver changes and perform block commit . ?
2. Has anyone tried with Qemu 2.4 for blockcommit and related operations ?
Does it work ?  (I know this might not be relevant to libvirt users for
sure it will help if someone trying block commit and related operations)

Thanks,
Keyur Bhalerao


On Tue, Dec 8, 2015 at 11:32 PM, Dominique Ramaekers <
dominique.ramaekers at cometal.be> wrote:

> This is not a libvirt/redhat question…
>
>
>
> With your method you can only revert to versions which are available in
> the standard repositories. You’ll have to download the packages manually to
> force a different version. Use with caution. There is a reason why the
> version isn’t in the standard repositories.
>
>
>
> *Van:* libvirt-users-bounces at redhat.com [mailto:
> libvirt-users-bounces at redhat.com] *Namens *Keyur Bhalerao
> *Verzonden:* woensdag 9 december 2015 0:05
> *Aan:* Kashyap Chamarthy
> *CC:* libvirt-users at redhat.com
> *Onderwerp:* Re: [libvirt-users] Efficient live disk backup with active
> blockcommit : Failed 'block-commit': Could not reopen file: Permission
> denied
>
>
>
> Hi
>
>
>
> Was trying to get specific qemu-kvm version. Do you know any way to get
> the 2.1.2 installed. Was trying sudo apt-get install qemu-kvm=1.2.1 but its
> not working.
>
>
>
> Tried with sudo apt-get install qemu-kvm tree=1.2.1
>
>
>
> But both have failed for Version not found.
>
>
>
> Thanks
>
> Keyur
>
>
>
>
>
> On Tue, Dec 8, 2015 at 11:21 AM, Keyur Bhalerao <keyurbhalerao at gmail.com>
> wrote:
>
> Thanks Kashyap for replying.
>
>
>
> QEMU has permissions to the directory which is having images. I will look
> into the AppArmor issue and find out more about this.
>
> Also as per suggestion from the link i have uncommented the user and group
> from the qemu.conf file - https://github.com/jedi4ever/veewee/issues/996
>
>
>
> By checking more on the AppArmor and sVirt issue  , i have modified the
> qemu.conf for security_driver="none". The result for this is no permission
> error but another error which can be related to QEMU 2.3.0
>
>
>
> virsh # blockcommit vm-01 vda --verbose --pivot --active
>
> Block Commit: [100 %]error: failed to pivot job for disk vda
>
> error: internal error: unable to execute QEMU command
> 'block-job-complete': The active block job for device 'drive-virtio-disk0'
> cannot be completed
>
>
>
> Searched more for this type of error and found -
>
>
>
> https://bugs.launchpad.net/qemu/+bug/1455475
>
>
>
> Looks like bug in QEMU 2.3.0 . Checking now with QEMU 2.1 for the same.
>
>
>
> Let me know if anything to more look for.
>
>
>
>
>
>
>
> Thanks,
>
> Keyur Bhalerao
>
>
>
>
>
> On Tue, Dec 8, 2015 at 5:18 AM, Kashyap Chamarthy <kchamart at redhat.com>
> wrote:
>
> On Mon, Dec 07, 2015 at 12:52:34PM -0800, Keyur Bhalerao wrote:
>
> [. . .]
>
>  ubuntu at keyurubuntu:~$ virsh blockcommit vm-01 vda --active --verbose
> --pivot
> > error: internal error: unable to execute QEMU command 'block-commit':
> Could
> > not reopen file: Permission denied
>
> Fairly obvious suggestions, ensure permissions are set so that QEMU has
> permissions to the dir that contains images.
>
> Or it could be an AppArmor issue.
>
> Also, check your logs:
>
>     /var/log/libvirt/qemu/$VM.log
>     /var/log/libvirt/libvirtd.log  (assuming you have debug logging
>     enabled)
>
>
> > I am not sure why this is getting as permission denied. I have tried
> > couple of times reinstalling and creating new VMs . Every time when i
> > have tried to block-commit getting landed into  same error.
> >
> > Is there any troubleshooting or solution to this issue. Stuck on this
> > issue for last 2 days.  Quick help much appreciated.
> >
> > Thanks, Keyur Bhalerao
> >
> > Reference used -
> > http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit
> > -
> > http://kashyapc.com/2012/09/14/externaland-live-snapshots-with-libvirt/
>
> --
> /kashyap
>
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/libvirt-users/attachments/20160105/5ac9ac93/attachment.htm>