similar to: [PATCH] lib: create: avoid one extra string allocation

If you use the libguestfs tools which open disk images read-only (eg. virt-df), with formats such as 'vdi', then you will see an error: error: invalid value for backingformat parameter 'vdi' This is because opening a disk image read-only will try to create a qcow2 file with the original image as a backing file. However the list of permitted backing formats was very restrictive

On Fri, Jun 23, 2017 at 04:12:35PM +0300, Pavel Butsykin wrote: > This feature allows you to use different image formats for the fixed > appliance. The raw format is used by default. > > Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> > --- > lib/create.c | 5 +++-- > lib/guestfs-internal.h | 2 ++ > lib/launch-direct.c | 2 ++ >

In the guestfs_disk_create API we have traditionally allowed you to set backingfile without setting backingformat. The meaning of this is to let qemu autodetect the backing format when opening the overlay disk. However libvirt >= 6.0 refuses to even pass such disks to qemu (see https://bugzilla.redhat.com/show_bug.cgi?id=1798148). For this reason, move the autodetection earlier and make it

For the appliance of the QCOW2 format, get the UUID of the disk by reading the first 256k bytes with 'qemu-img dd' command. Then pass the read block to the 'file' command. In case of failure, run the 'file' command again directly. Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> --- v2: 01: The

The main purpose of this change is two-fold: (1) Ensure that we run the same version of qemu-img that we are built against. (2) Allow the qemu-img path to be overridden at build time in case it's on a nonstandard path or (like RHV) has a nonstandard name. --- docs/guestfs-building.pod | 6 ++++++ lib/command.c | 4 ++-- lib/create.c | 4 ++-- lib/info.c

For the appliance of the QCOW2 format, the function get_root_uuid() fails to get the UUID of the disk image. In this case, let us read the first 256k bytes of the disk image with the 'qemu-img dd' command. Then pass the read block to the 'file' command. Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> ---

See http://rwmj.wordpress.com/2014/11/23/mapping-files-to-disk/

On Mon, Mar 09, 2020 at 11:07:20AM +0100, Pino Toscano wrote: > On Thursday, 6 February 2020 18:20:19 CET Richard W.M. Jones wrote: > > In the guestfs_disk_create API we have traditionally allowed you to > > set backingfile without setting backingformat. The meaning of this is > > to let qemu autodetect the backing format when opening the overlay > > disk. > >

Commit 588af1953e5f7ab74009b9175cc5d3efb8bb651a started with a very conservative list of permitted backing formats (just "raw" or "qcow2"). We can allow almost any format permitted by qemu, but this commit just adds "vmdk" to this whitelist. --- src/create.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/create.c b/src/create.c index

A lot of code runs 'qemu-img create' or 'truncate' to create blank disk images. In the past I resisted adding an API to do this, since it essentially duplicates what you can already do using other tools (ie. qemu-img). However this does simplify calling code quite a lot since qemu-img is somewhat error-prone to use (eg: don't try to create a disk called "foo:bar")

On Mon, Mar 09, 2020 at 12:07:08PM +0100, Pino Toscano wrote: > On Monday, 9 March 2020 11:40:46 CET Richard W.M. Jones wrote: > > On Mon, Mar 09, 2020 at 11:07:20AM +0100, Pino Toscano wrote: > > > On Thursday, 6 February 2020 18:20:19 CET Richard W.M. Jones wrote: > > > > In the guestfs_disk_create API we have traditionally allowed you to > > > > set

On Friday, 15 December 2017 09:26:29 CET Richard W.M. Jones wrote: > It obscures what's really going on and is no longer necessary > for the original purpose. > > This reverts commit d50cb7bbb4cc18f69ea1425e9f5cee9685825f95. > > See also: > > https://www.redhat.com/archives/libguestfs/2017-November/thread.html#00226 >

v1 posted here: https://www.redhat.com/archives/libguestfs/2017-December/msg00050.html v2 fixes the tests by rewriting relative paths as ./filename (so that filenames like "file:foo" work).

libguestfs has used double and triple underscores in identifiers. These aren't valid for global names in C++. (http://stackoverflow.com/a/228797) These large but completely mechanical patches change the illegal identifiers to legal ones. Rich.

For the appliance of the QCOW2 format, get the UUID of the disk by reading the first 256k bytes with 'qemu-img dd' command. Then pass the read block to the 'file' command. In case of failure, run the 'file' command again directly. Suggested-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com> ---

On Thu, Aug 13, 2020 at 07:48:52AM +0300, Andrey Shinkevich wrote: > For the appliance of the QCOW2 format, the function get_root_uuid() > fails to get the UUID of the disk image. > In this case, let us read the first 256k bytes of the disk image with > the 'qemu-img dd' command. Then pass the read block to the 'file' > command. > > Suggested-by: Denis V.

On Wed, Aug 12, 2020 at 03:52:34PM +0300, Vladimir Sementsov-Ogievskiy wrote: > 12.08.2020 15:39, Andrey Shinkevich wrote: > >For the appliance of the QCOW2 format, get the UUID of the disk by > >reading the first 256k bytes with 'qemu-img dd' command. Then pass the > >read block to the 'file' command. In case of failure, run the 'file' > >command

On Wed, Aug 12, 2020 at 04:12:28PM +0300, Vladimir Sementsov-Ogievskiy wrote: > 12.08.2020 15:52, Vladimir Sementsov-Ogievskiy wrote: > >12.08.2020 15:39, Andrey Shinkevich wrote: > >>For the appliance of the QCOW2 format, get the UUID of the disk by > >>reading the first 256k bytes with 'qemu-img dd' command. Then pass the > >>read block to the

On Thursday, 6 February 2020 18:20:19 CET Richard W.M. Jones wrote: > In the guestfs_disk_create API we have traditionally allowed you to > set backingfile without setting backingformat. The meaning of this is > to let qemu autodetect the backing format when opening the overlay > disk. > > However libvirt >= 6.0 refuses to even pass such disks to qemu (see >

On Monday, 9 March 2020 11:40:46 CET Richard W.M. Jones wrote: > On Mon, Mar 09, 2020 at 11:07:20AM +0100, Pino Toscano wrote: > > On Thursday, 6 February 2020 18:20:19 CET Richard W.M. Jones wrote: > > > In the guestfs_disk_create API we have traditionally allowed you to > > > set backingfile without setting backingformat. The meaning of this is > > > to let