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no-senders; approved; loop; banned-address; header-match-devel.lists.libvirt.org-0; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Development discussions about the libvirt library & tools Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: From: Peter Krempa via Devel Reply-To: Peter Krempa X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1760363402524154100 Content-Type: text/plain; charset="utf-8" From: Peter Krempa Using a blockjob will reactivate the block nodes in qemu and thus e.g. qcow2 metadata such as bitmaps may become marked as dirty. Users of 'manual' snapshots ought to avoid those. Signed-off-by: Peter Krempa --- docs/formatsnapshot.rst | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/docs/formatsnapshot.rst b/docs/formatsnapshot.rst index b85194b6bb..98e3adc235 100644 --- a/docs/formatsnapshot.rst +++ b/docs/formatsnapshot.rst @@ -127,9 +127,12 @@ The top-level ``domainsnapshot`` element may contain t= he following elements: :since:`Since 8.2.0` the ``snapshot`` attribute supports the ``manua= l`` value which instructs the hypervisor to create the snapshot and keep= a - synchronized state by pausing the VM which allows to snapshot disk + synchronized state by pausing the VM (and where supported deactivati= ng + the storage backends of the hypervisor), which allows to snapshot di= sk storage from outside of the hypervisor if the storage provider suppo= rts - it. The caller is responsible for resuming a VM paused by requestin= g a + it. VM operations requiring the storage (e.g. blockjobs, migration)= should + be avoided to ensure that the storage backends can stay deactivated. + The caller is responsible for resuming a VM paused by requesting a ``manual`` snapshot. When reverting such snapshot, the expectation i= s that the storage is configured in a way where the hypervisor will see the correct image state. --=20 2.51.0