Re: [PATCH 3/4] virDomainCheckpointCreateXML: Add disclaimer about creating checkpoints
On 8/23/22 6:32 AM, Peter Krempa wrote:
Checkpoints created via virDomainCheckpointCreateXML are generally
not
very useful as they need to be coupled with a backup.
Add a disclaimer to the docs explaining why users should use
virDomainBackupBegin instead.
Signed-off-by: Peter Krempa <pkrempa(a)redhat.com>
---
src/libvirt-domain-checkpoint.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/src/libvirt-domain-checkpoint.c b/src/libvirt-domain-checkpoint.c
index de747aff01..078e999bf3 100644
--- a/src/libvirt-domain-checkpoint.c
+++ b/src/libvirt-domain-checkpoint.c
@@ -142,6 +142,16 @@ virDomainCheckpointGetConnect(virDomainCheckpointPtr checkpoint)
* present, an error is thrown. This flag is incompatible with
* VIR_DOMAIN_CHECKPOINT_CREATE_REDEFINE.
*
+ * Note: A checkpoint represent s point in time since which blocks changed by
+ * the hypervisor are tracked.
extra space in "represent s"
Also, I think it would be more clearly understood if we changed "since"
to "after".
"Note: a checkpoint represents a point in time after which blocks
changed..."
This means that
+ * for a checkpoint to be generally usable for doing an incremental backup it's
+ * required to perform a backup at the same time as taking the checkpoint.
I might suggest something like:
"The main purpose of checkpoints is to enable incremental backups. But
for a checkpoint to be useful for this purpose, a backup should be
performed at the same time as the checkpoint is created."
+ * This is done via the virDomainBackupBegin API, which also allows
to create
+ * a checkpoint at the same time. virDomainCheckpointCreateXML is generally not
+ * useful for creating checkpoints but rather only for re-creating the libvirt
+ * metadata.
my suggestion here:
"This is done via the virDomainBackupBegin API, which also allows to
create a checkpoint at the same time. Creating checkpoints with
virDomainCheckpointCreateXML is generally only useful for re-creating
the libvirt metadata"
Reviewed-by: Jonathon Jongsma <jjongsma(a)redhat.com>