But for me there is no element for the value of space. It looks something like this:
<disk_attachment
href="/ovirt-engine/api/vms/678faf6f-fa5f-4785-a365-e1b85925575f/diskattachments/f770c0d1-dd0d-40a8-a69a-a63d8db5c2cc"
id="f770c0d1-dd0d-40a8-a69a-a63d8db5c2cc">
<active>true</active>
<bootable>true</bootable>
<interface>virtio_scsi</interface>
<pass_discard>false</pass_discard>
<read_only>false</read_only>
<uses_scsi_reservation>false</uses_scsi_reservation>
<disk href="/ovirt-engine/api/disks/f770c0d1-dd0d-40a8-a69a-a63d8db5c2cc"
id="f770c0d1-dd0d-40a8-a69a-a63d8db5c2cc"/>
<vm href="/ovirt-engine/api/vms/678faf6f-fa5f-4785-a365-e1b85925575f"
id="678faf6f-fa5f-4785-a365-e1b85925575f"/>
</disk_attachment>
So is it not possible to increase extend space using the API in ovirt?