On Mon, May 21, 2018 at 05:28:18PM +0200, Pino Toscano wrote: > Commit 4699c7b6e126e07c95b67fb95df58aed87a680dd converted the null > output to use the null-co qemu driver with a JSON URL syntax -- > especially the latter is only available in newer versions of qemu. > > Even if this output mode is mostly for testing, check at runtime whether > the null-co + JSON way is possible, falling back to the creation of > thrown-away temporary files as before. > --- > v2v/output_null.ml | 60 +++++++++++++++++++++++++++++++++++++--------- > 1 file changed, 49 insertions(+), 11 deletions(-) > > diff --git a/v2v/output_null.ml b/v2v/output_null.ml > index b93d53dc5..5a5473c0d 100644 > --- a/v2v/output_null.ml > +++ b/v2v/output_null.ml > @@ -42,7 +42,37 @@ open Utils > * size instead. > *) > > +let qemu_supports_null_co_device () = > + (* We actually attempt to convert a raw file to the null-co device. *) > + let tmp = Filename.temp_file "v2vqemunullcotst" ".img" in > + Unix.truncate tmp 1024; > + > + let json = [ > + "file.driver", JSON.String "null-co"; > + "file.size", JSON.String "1E"; > + ] in > + > + let cmd = > + sprintf "qemu-img convert -n -f raw -O raw %s json:%s >/dev/null%s" > + (quote tmp) > + (quote (JSON.string_of_doc ~fmt:JSON.Compact json)) > + (if verbose () then "" else " 2>&1") in > + debug "%s" cmd; > + let r = 0 = Sys.command cmd in > + Unix.unlink tmp; > + debug "qemu-img supports the null-co device: %b" r; > + r
I wonder if for consistency we should put this into v2v/utils.ml, and also add a test to v2v/v2v_unit_tests.ml ... (although the test for Utils.qemu_img_supports_offset_and_size is kinda useless). Rest of the patch looks good to me, so ACK. Thanks, Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ Libguestfs mailing list [email protected] https://www.redhat.com/mailman/listinfo/libguestfs
