Re: [Libguestfs] [Qemu-block] v2v: -o rhv-upload: Long time spent zeroing the disk

On Thu, Apr 12, 2018 at 2:07 AM Nir Soffer <nirsof(a)gmail.com&gt; wrote: ... I think we can expose NBD using ndb-server and dynamic exports. It can work like this: 0. Install nbd and enable nbd-server on a host, running as vdsm:kvm, not exporting anything. 1. User starts transfer session via oVirt API with protocol="nbd" (if not specified, use "https" for backward compatibility) 2. oVirt selects a host for the transfer and configures an export in that host - for example: [bbff5ab7-2e8e-45b8-a497-423c2d2b3ff1] exportname = /path/to/image trim = yes timeout = 300 nbd-server supports reloading configuration via SIGHUP. Looks like it should work for adding export dynamically: https://github.com/NetworkBlockDevice/nbd/blob/cb6e816c4d2c536cfff5ba9859... I could find code handling removing exports. 3. User gets back - transfer_url: "nbd:hostname:port" - export_name: bbff5ab7-2e8e-45b8-a497-423c2d2b3ff1 Assuming that if NBD_OPT_EXPORT_NAME is bbff5ab7-2e8e-45b8-a497-423c2d2b3ff1 ndb-server will export the /path/to/image mentioned in the config exportname. This seems to be the case based on: - https://github.com/NetworkBlockDevice/nbd/blob/master/nbd-server.c#L998 - https://github.com/NetworkBlockDevice/nbd/blob/cb6e816c4d2c536cfff5ba9859... 4. User transmit data using nbd-client or qemu-img or maybe a wrapper script to make it easier 5. During the transfer, oVirt monitors progress and activity. I don't see how we can do this with current nbd-server. 6. User ends the transfer session via oVirt API 7. oVirt removes the export and finalize the transfer. I guess this can work in a similar way for KubeVirt. The way the image is provisioned and attached to a host will be different, but the way a user will transfer image data can be the same. Seems that nbd-server is missing: - way to remove exports dynamically - way to monitor export activity and progress Nir