Re: [Libguestfs] nbdkit: cow.c:591: cow_extents: Assertion `count > 0' failed.

On Sat, Jul 24, 2021 at 11:17:43AM +0100, Richard W.M. Jones wrote: I was wrong about cacheextents. Here's the simplest reproducer I can come up with: $ ./nbdkit curl https://download.fedoraproject.org/pub/fedora/linux/releases/34/Cloud/x86... --filter=cow --filter=xz --run 'nbdinfo --map $uri' nbdkit: cow.c:591: cow_extents: Assertion `count > 0' failed. It also happens if I download that cloud image and use the file plugin: $ ./nbdkit file Fedora-Cloud-Base-34-1.2.x86_64.raw.xz --filter=cow --filter=xz --run 'nbdinfo --map $uri' nbdkit: cow.c:591: cow_extents: Assertion `count > 0' failed. Weird that we've not seen this before ... Rich. -- 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/