Re: [Libguestfs] [PATCH 2/5] v2v/lib/util.ml: Get disk allocation from input

On Sat, Dec 18, 2021 at 10:36:30PM +0200, Nir Soffer wrote: > After finalizing the transfer, virt-v2v try to connect to the output > socket and query disk allocation. This may work for some outputs > supporting block status, but for rhv_upload output this cannot work for > 2 reasons: > - The rhv-upload-plugin does not support extents > - The transfer was finalized before this call, so the plugin lost access > to the image. > > Here is an example failure log: > > [ 74.2] Creating output metadata > python3 '/tmp/v2v.WMq8Tk/rhv-upload-finalize.py' '/tmp/v2v.WMq8Tk/params6.json' > finalizing transfer b03fe3ba-a4ff-4634-a0a0-10b3daba3cc2 > ... > transfer b03fe3ba-a4ff-4634-a0a0-10b3daba3cc2 finalized in 2.118 seconds > ... > nbdkit: debug: accepted connection > ... > nbdkit: python[4]: debug: python: close > virt-v2v: error: exception: NBD.Error("nbd_block_status: request out of > bounds: Invalid argument", 22) > > Fix by using the input socket. > --- > lib/utils.ml | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/utils.ml b/lib/utils.ml > index d6861d08..f6c85543 100644 > --- a/lib/utils.ml > +++ b/lib/utils.ml > @@ -171,21 +171,21 @@ let with_nbd_connect_unix ~socket ~meta_contexts ~f = > ~f:(fun () -> > List.iter (NBD.add_meta_context nbd) meta_contexts; > NBD.connect_unix nbd socket; > protect > ~f:(fun () -> f nbd) > ~finally:(fun () -> NBD.shutdown nbd) > ) > ~finally:(fun () -> NBD.close nbd) > > let get_disk_allocated ~dir ~disknr = > - let socket = sprintf "%s/out%d" dir disknr > + let socket = sprintf "%s/in%d" dir disknr This patch is definitely wrong - we need to get the allocation size from the output disk. Options such as -oa preallocated, and just general issues like block size, nbdcopy sparseness detection etc, would affect this. It probably indicates a problem with rhv-upload-plugin (again) that it's not really prepared to be an idempotent part of a disk image pipeline.

Rich. > and alloc_ctx = "base:allocation" in > with_nbd_connect_unix ~socket ~meta_contexts:[alloc_ctx] > ~f:(fun nbd -> > if NBD.can_meta_context nbd alloc_ctx then ( > (* Get the list of extents, using a 2GiB chunk size as hint. *) > let size = NBD.get_size nbd > and allocated = ref 0_L > and fetch_offset = ref 0_L in > while !fetch_offset < size do > let remaining = size -^ !fetch_offset in > -- > 2.33.1 -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-df lists disk usage of guests without needing to install any software inside the virtual machine. Supports Linux and Windows. http://people.redhat.com/~rjones/virt-df/