Re: [PATCH v4 03/11] qemu: snapshot: Introduce helpers for creating overlays on <transient/> disks
On 9/24/20 6:43 AM, Peter Krempa wrote:
To implement <transient/> disks we'll need to install an
overlay on top
of the original disk image which will be discarded after the VM is
turned off. This was initially implemented by qemu but libvirt never
picked up this option. With blockdev the qemu feature became unsupported
You may want to add mention that qemu's -transient command-line option
lets qemu create the file, which fails under various SELinux scenarios
(as one of the reasons why libvirt never used it).
so we need to do this via the snapshot code anyways.
The helpers introduced in this patch prepare a fake snapshot disk
definition for a disk which is configured as <transient/> and use it to
create a snapshot (without actually modifying metada or persistent def).
metadata
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/qemu/qemu_snapshot.c | 91 +++++++++++++++++++++++++++++++++++++++-
src/qemu/qemu_snapshot.h | 5 +++
2 files changed, 95 insertions(+), 1 deletion(-)
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org