[Qemu-discuss] One question about "drive-backup"

[David Lee]

Hi, list

I was trying "drive-backup" for incremental backups, and so far so
good for individual drives.
The question is that, when I grouped the drive-backup into a
transaction, I got errors like:

{"id":"libvirt-377183","error":{"class":"GenericError","desc":"a
sync_bitmap was provided to backup_run, but received an incompatible
sync_mode (top)"}}

It is also the case when sync mode is changed to 'full'.  And the only
valid mode seems to be
'incremental', which is exactly what's documented in:
  
https://github.com/qemu/qemu/blob/master/docs/interop/bitmaps.rst#partial-transactional-failures

But, there are no warnings saying that only 'incremental' sync mode
can be grouped into a transaction.

Any suggestion on taking multiple drive-backups without sync mode =
'incremental'?

Thanks in advance.


PS. here is the snippet of my QMP command:
----cut begin----
{
 "execute": "transaction",
 "arguments": {
   "actions": [
     {
       "type": "drive-backup",
       "data": {
         "device": "drive-virtio-disk0",
         "target": "/opt/backups/82faf05a-2cad-43a7-b9d6-9c78075534fe.qcow2",
         "bitmap": "bitmap0",
         "job-id": "job-516",
         "sync": "top",
         "format": "qcow2"
       }
     },
     {
       "type": "drive-backup",
       "data": {
         "device": "drive-scsi0-0-0-1",
         "target": "/opt/backups/6ee3e2d4-6e40-49d5-b15f-ff20c0aafbee.qcow2",
         "bitmap": "bitmap1",
         "job-id": "job-517",
         "sync": "top",
         "format": "qcow2"
       }
     }
   ],
}
----cut ends----

-- 
Thanks,
Li Qun