On Tue, Jul 7, 2020 at 5:05 PM Łukasz Kołaciński <l.kolacinski@storware.eu> wrote:

Dear ovirt community,

Hi Łukasz,

Adding devel@ovit.org since this topic is more appropriate for the devel list.

 

I am trying to use ovirt imageio api to receive changed blocks (dirty bitmap) on ovirt 4.4. Could anyone tell me how to get them step by step? On the documentation I saw endpoint "GET /images/ticket-uuid/map". I don't know what ticket-uuid is and how to generate it. I also need to know how to use this api because I can't reach it via /ovirt-engine/api/

I am asking about this endpoint:

https://www.ovirt.org/documentation/incremental-backup-guide/incremental-backup-guide.html#imageio-backup-api

This guide is outdated and should not be used now.

The most up to date information is here:

https://www.ovirt.org/develop/release-management/features/storage/incremental-backup.html

However the extents API is also outdated in the feature page. We are working on updating it.

So here is example:

First you must start backup with from_checkpoint_id argument:

    backup = backups_service.add(
        types.Backup(
            disks=disks,
            from_checkpoint_id="checkpoint-id",
        )
    )   

"checkpoint-id" is the checkpoint created in the last backup.

This starts a backup in in incremental mode. Dirty extents are available only

in this mode.

Then you start a transfer for download, using the backup id:

    transfer = imagetransfer.create_transfer(
        connection,
        disk,
        types.ImageTransferDirection.DOWNLOAD,
        backup=types.Backup(id=backup_uuid))

The transfer.transfer_url is the URL to download from, for example:

    https://host:54322/images/53787351-3f72-44a1-8a26-1323524fac4a

Connect to host:54322 and send this request:

    GET /images/53787351-3f72-44a1-8a26-1323524fac4a/extents?context=dirty

And parse the return json list, containing objects like:

[

    {"start": 0, "length": 65536, "dirty": true},

    {"start": 65536, "length": 1048576, "dirty": false},

    ...

]

For example code of using the imageio API, see imageio http backend:

https://github.com/oVirt/ovirt-imageio/blob/d5aa0e1fe659f1bf1247516f83c71e072803fa05/daemon/ovirt_imageio/_internal/backends/http.py#L288

https://github.com/oVirt/ovirt-imageio/blob/d5aa0e1fe659f1bf1247516f83c71e072803fa05/daemon/ovirt_imageio/_internal/backends/http.py#L498

We are adding a ImageioClient API that makes it easier to consume without

writing any HTTP code:

https://gerrit.ovirt.org/c/110068

With this you can use:

    with ImageioClient(transfer.transfer_url, cafile=args.cafile) as client:

        for extent in client.extent("dirty"):

            if extent.dirty:

                print("##dirty start={} length={}".format(extent.start, extent.length))

                client.write_to(sys.stdout.buffer, extent.start, extent.length)

                print()

This will stream the dirty extents to stdout. Not very useful as is, but illustrates how

you can consume the data.

Here is an example writing extents to a sparse stream format:

https://gerrit.ovirt.org/c/110069

For complete backup example code see:

https://github.com/oVirt/ovirt-engine-sdk/blob/master/sdk/examples/backup_vm.py

Note the new imagetransfer helper module:

https://github.com/oVirt/ovirt-engine-sdk/blob/master/sdk/examples/helpers/imagetransfer.py

Nir

e-mail: l.kolacinski@storware.eu

 

ul. Leszno 8/44 01-192 Warszawa www.storware.eu

 

Storware Spółka z o.o. nr wpisu do ewidencji KRS dla M.St. Warszawa 000510131 , NIP 5213672602. Wiadomość ta jest przeznaczona jedynie dla osoby lub podmiotu, który jest jej adresatem i może zawierać poufne i/lub uprzywilejowane informacje. Zakazane jest jakiekolwiek przeglądanie, przesyłanie, rozpowszechnianie lub inne wykorzystanie tych informacji lub podjęcie jakichkolwiek działań odnośnie tych informacji przez osoby lub podmioty inne niż zamierzony adresat. Jeżeli Państwo otrzymali przez pomyłkę tę informację prosimy o poinformowanie o tym nadawcy i usunięcie tej wiadomości z wszelkich komputerów. This message is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you have received this message in error, please contact the sender and remove the material from all of your computer systems.

_______________________________________________
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-leave@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/
List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/AIJMMJOR354VKVWWZZL74VKOEUEBO45Q/

_______________________________________________
Users mailing list -- users@ovirt.org
To unsubscribe send an email to users-leave@ovirt.org
Privacy Statement: https://www.ovirt.org/privacy-policy.html
oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/
List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/S6OR7YRZCJMAWOHW62SJX3FUXJIZHQTG/