Re: [Qemu-devel] "File too large" error from "qemu-img snapshot" (was Re: AW: Bug Repoting Directions Request)

[Paolo Bonzini <pbonzini@redhat.com>]

On 22/11/2014 18:02, Prof. Dr. Michael Schefczyk wrote:
> The further features seem to be reserved to RHEL (and potentially
> other distributions) but not included in Centos:
> 
> virsh snapshot-create-as issues "Live Disk Snapshot not supported in
> this version of QEMU" (retranslated from German).
> 
> virsh blockcommit issues "Online Transfer not supported ..."
> 
> Thus, with Centos 7 it should be possible to back up VMs without
> shutting them down. They are being paused, however, as long as the
> snapshot is created. The qemu-guest-agent does not help in this
> context, as the features which depend on it are not available in
> Centos.

Actually, they are available in most distributions except RHEL and 
CentOS.  For various reasons that I cannot really detail here, Red Hat 
is only shipping these features as part of the "Red Hat Cloud 
Infrastructure" product.

Luckily, since you are using CentOS you do not really care about 
official Red Hat RPMs, and you can get the packages here:

http://resources.ovirt.org/pub/ovirt-3.5/rpm/el7Server/

This yum repository file will help:

    [qemu-kvm-rhev]
    name=oVirt rebuilds of qemu-kvm-rhev
    baseurl=http://resources.ovirt.org/pub/ovirt-3.5/rpm/el7Server/
    mirrorlist=http://resources.ovirt.org/pub/yum-repo/mirrorlist-ovirt-3.5-el7Server
    enabled=1
    skip_if_unavailable=1
    gpgcheck=0

Drop it in /etc/yum.repos.d/qemu-kvm-rhev.repo and install qemu-kvm-rhev
with yum.  All features will be available.  It would be simpler to have
a CentOS SIG build this, but it hasn't happened yet.

Thanks,

Paolo