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

[David Lee]

Thank you, Fam.

I did the following, and this time QEMU doesn't complain anything.
But what's the semantics of omitting the "bitmap" parameters?
And, how to continue with incremental backups after that?

If I repeat the snippet below, there will be error message:
{"id":"libvirt-381290","error":{"class":"GenericError","desc":"Need a
root block node"}}

What's happening?

Thanks for your patience.

```
{
 "execute": "transaction",
 "arguments": {
   "actions": [
     {
       "type": "drive-backup",
       "data": {
         "device": "drive-virtio-disk0",
         "target": "/tmp/vda-inc.qcow2",
         "job-id": "bak-job1",
         "sync": "top",
         "format": "qcow2"
       }
     },
     {
       "type": "drive-backup",
       "data": {
         "device": "drive-scsi0-0-0-1",
         "target": "/tmp/sdb-inc.qcow2",
         "job-id": "bak-job2",
         "sync": "top",
         "format": "qcow2"
       }
     }
   ],
```
On Wed, Aug 22, 2018 at 10:59 PM Fam Zheng <address@hidden> wrote:
>
> On Wed, 08/22 22:20, David Lee wrote:
> > 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'?
>
> Drop the 'bitmap' parameters if you're not doing incremental backup?
>
> Fam
>
> >
> > 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
> >



-- 
Thanks,
Li Qun