[libvirt] QEMU's File Descriptors

[Christopher Pereira]

>> Does libvirt currently reopen image files when resuming a VM?
>
> We might probe them, but that's it for now from what I know.  QEMU
> opens its file descriptors for them.  We are passing FDs now for tap
> network interface and similar, not for disks.
Yes. If we pass file descriptors, we may want to probe and reopen them 
to make the whole solution robust.
> I have no idea what gluster does under the hood, but if it messes up
> QEMU, then it's most probably not libvirt's fault.  We can't be 100%
> fool-proof and whatever-proof.
Let's suppose that our image files are on a folder that gets remounted 
and QEMU's file descriptors go into a bad state (still an hypothesis).
If we are passing file descriptors (disk and network) we may need to 
reopen them in libvirt.
If we are passing paths and sending QEMU something like a "resume" 
command, then QEMU should reopen them.

> Do you have the number?
https://bugzilla.redhat.com/show_bug.cgi?id=1058300

I didn't have the link before, since I wrote from my Android (UTC-4).

Best regards.