On Thu, Nov 08, 2012 at 04:24:51PM +0100, Ján Tomko wrote: > Currently the 'allocation' element is not used when creating new images > with qemu-img. This patch interprets a non-zero value as a request to > preallocate metadata when a qcow2 image is created. > > Bug: https://bugzilla.redhat.com/show_bug.cgi?id=684793 > --- > src/storage/storage_backend.c | 19 +++++++++++++------ > 1 files changed, 13 insertions(+), 6 deletions(-) > > diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c > index 41a19a1..bf6f7cc 100644 > --- a/src/storage/storage_backend.c > +++ b/src/storage/storage_backend.c > @@ -669,10 +669,15 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, > int imgformat = -1; > virCommandPtr cmd = NULL; > bool do_encryption = (vol->target.encryption != NULL); > + bool preallocate = false; > unsigned long long int size_arg; > > virCheckFlags(0, -1); > > + /* qcow2: preallocate metadata if requested allocation is non-zero */ > + if (vol->allocation > 0 && vol->target.format == VIR_STORAGE_FILE_QCOW2) > + preallocate = true; > + > const char *type = virStorageFileFormatTypeToString(vol->target.format); > const char *backingType = vol->backingStore.path ? > virStorageFileFormatTypeToString(vol->backingStore.format) : NULL;> @@ -842,12 +847,14 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, > vol->target.path, NULL); > virCommandAddArgFormat(cmd, "%lluK", size_arg); > > - if (do_encryption) { > - if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS) { > - virCommandAddArgList(cmd, "-o", "encryption=on", NULL); > - } else { > - virCommandAddArg(cmd, "-e"); > - } > + if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS && > + (do_encryption || preallocate)) { > + virCommandAddArg(cmd, "-o"); > + virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "", > + (do_encryption && preallocate) ? "," : "", > + preallocate ? "preallocation=metadata" : ""); > + } else if (do_encryption){ > + virCommandAddArg(cmd, "-e"); > } > } I've thought about doing it this way before, but I always felt it was a bit of a gross hack. It would be nice to keep the 'allocation' element as purely describing the data sector allocation. I was recently wondering if we should just add a flag to the virStorageVolCreate like VIR_STORAGE_VOL_PREALLOC_METADATA Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list