[ovirt-users] Re: Using ovirt imageio

On Tue, Jul 7, 2020 at 5:05 PM Łukasz Kołaciński <l.kolacinski(a)storware.euwrote: Hi Łukasz, Adding devel(a)ovit.org since this topic is more appropriate for the devel list. This guide is outdated and should not be used now.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/increme... However the extents API is also outdated in the feature page.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/d5aa0e1fe659f1bf1247516f83c71... https://github.com/oVirt/ovirt-imageio/blob/d5aa0e1fe659f1bf1247516f83c71... 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... Note the new imagetransfer helper module: https://github.com/oVirt/ovirt-engine-sdk/blob/master/sdk/examples/helper... Nir e-mail: l.kolacinski(a)storware.eu > <m.helbert(a)storware.eu> *[image: STORWARE]* <http://www.storware.eu/> *ul. Leszno 8/44 01-192 Warszawa www.storware.eu > <https://www.storware.eu/>* > *[image: facebook]* <https://www.facebook.com/storware> *[image: twitter]* <https://twitter.com/storware> *[image: linkedin]* <https://www.linkedin.com/company/storware> *[image: Storware_Stopka_09]* > <https://www.youtube.com/channel/UCKvLitYPyAplBctXibFWrkw> *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(a)ovirt.org > To unsubscribe send an email to users-leave(a)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/AIJMMJOR354...