Re: [PATCH 1/3] conf: snapshot: Introduce 'manual' mode for snapshot of a disk

The idea of the manual mode is to allow a synchronized snapshot in cases when the storage is outsourced to an unmanaged storage provider which requires cooperation with snapshotting. The mode will instruct the hypervisor to pause along when the other components are snapshotted and the 'manual' disk can be snapshotted along. This increases latency of the snapshot but allows them in otherwise impossible situations. Signed-off-by: Peter Krempa <pkrempa(a)redhat.com&gt; --- docs/formatdomain.rst | 15 ++++++++------- docs/formatsnapshot.rst | 9 +++++++++ docs/schemas/domainsnapshot.rng | 3 +++ src/conf/domain_conf.c | 1 + src/conf/domain_conf.h | 1 + src/conf/snapshot_conf.c | 6 ++++++ src/qemu/qemu_snapshot.c | 5 +++++ src/test/test_driver.c | 17 +++++++++++++++++ 8 files changed, 50 insertions(+), 7 deletions(-) diff --git a/docs/formatsnapshot.rst b/docs/formatsnapshot.rst index 0fee35d89c..4635df89cb 100644 --- a/docs/formatsnapshot.rst +++ b/docs/formatsnapshot.rst @@ -124,6 +124,15 @@ The top-level ``domainsnapshot`` element may contain the following elements: corresponding domain disk, while others like qemu allow this field to override the domain default. + :since:`Since 8.2.0` the ``snapshot`` attribute supports the ``manual`` + value which instructs the hypervisor to create the snapshot and keep a + synchronized state by pausing the VM which allows to snapshot disk + storage from outside of the hypervisor if the storage provider supports + it. The caller is responsible for resuming a VM paused by requesting a + ``manual`` snapshot When reverting such snapshot, the expectation is that

+ the storage is configured in a way where the hypervisor will see the + correct image state. + :since:`Since 1.2.2` the ``disk`` element supports an optional attribute ``type`` if the ``snapshot`` attribute is set to ``external``. This attribute specifies the snapshot target storage type and allows to