Re: [Xen-devel] XEN Qdisk Ceph rbd support broken?

[Brian Marcotte <marcotte@panix.com>]

This issue with Xen 4.13 and Ceph/RBD was last discussed back in February.

> Remote network Ceph image works fine with Xen 4.12.x ...
> 
> In Xen 4.13.0 which I have tested recently it blames with the error
> message "no such file or directory" as it would try accessing the image
> over filesystem instead of remote network image.
> ---
> 
> I doubt the issue is in xl/libxl; sounds more likely to be in QEMU. The
> PV block backend infrastructure in QEMU was changed between the 4.12
> and 4.13 releases. Have you tried using an older QEMU with 4.13?

I'm also encountering the problem:

    failed to create drive: Could not open 'rbd:rbd/machine.disk0': No such file or directory

Xenstore has "params" like this:

    aio:rbd:rbd/machine.disk0

If I set it to "rbd:rbd/machine.disk0", I get a different message:

  failed to create drive: Parameter 'pool' is missing

Using upstream QEMU versions 2 or 3 works fine.

The interesting thing is that access by the virtual BIOS works fine. So,
for a PVHVM domain, GRUB loads which loads a kernel, but the kernel can't
access the disks.

--
- Brian