Libguestfs - Mar 2017 - Re: [PATCH] v2v: xen: Require direct backend when doing Xen conversions over SSH.

From: "Richard W.M. Jones" <rjones@redhat.com>

Unfortunately libvirt has another bug related to the qemu
ssh driver, as described here:

https://bugzilla.redhat.com/show_bug.cgi?id=1434651#c3

Until this bug is fixed we have to require the direct backend to be
used for xen+ssh conversions.

This partially reverts commit ecbf09385033ba0acf14e914927ec81ad20a5308.
---
 v2v/input_libvirt_xen_ssh.ml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/v2v/input_libvirt_xen_ssh.ml b/v2v/input_libvirt_xen_ssh.ml
index 4975eff..a68cdf8 100644
--- a/v2v/input_libvirt_xen_ssh.ml
+++ b/v2v/input_libvirt_xen_ssh.ml
@@ -38,6 +38,9 @@ object
     debug "input_libvirt_xen_ssh: source: scheme %s server %s"
           scheme server;
 
+    if backend_is_libvirt () then (
+      error (f_"because of libvirt bug https://bugzilla.redhat.com/1434651
you must set this environment variable:\n\nexport
LIBGUESTFS_BACKEND=direct\n\nand then rerun the virt-v2v command.")
+    );
     error_if_libvirt_does_not_support_json_backingfile ();
     error_if_no_ssh_agent ();
 
-- 
1.8.3.1

On Wednesday, 22 March 2017 16:46:13 CET Richard W.M. Jones
wrote:
> From: "Richard W.M. Jones" <rjones@redhat.com>
> 
> Unfortunately libvirt has another bug related to the qemu
> ssh driver, as described here:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1434651#c3
> 
> Until this bug is fixed we have to require the direct backend to be
> used for xen+ssh conversions.
> 
> This partially reverts commit ecbf09385033ba0acf14e914927ec81ad20a5308.
> ---
>  v2v/input_libvirt_xen_ssh.ml | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/v2v/input_libvirt_xen_ssh.ml b/v2v/input_libvirt_xen_ssh.ml
> index 4975eff..a68cdf8 100644
> --- a/v2v/input_libvirt_xen_ssh.ml
> +++ b/v2v/input_libvirt_xen_ssh.ml
> @@ -38,6 +38,9 @@ object
>      debug "input_libvirt_xen_ssh: source: scheme %s server %s"
>            scheme server;
>  
> +    if backend_is_libvirt () then (
> +      error (f_"because of libvirt bug
https://bugzilla.redhat.com/1434651 you must set this environment
variable:\n\nexport LIBGUESTFS_BACKEND=direct\n\nand then rerun the virt-v2v
command.")
> +    );
LGTM if you amend the bug number to RHBZ#1140166 in commit log and
error message.

Should this also be documented briefly in the manual? I.e. mention that,
due to libvirt limitations, Xen conversions using the libvirt backend
will not work, and this the direct backend is needed.

Thanks,
-- 
Pino Toscano

On Thu, Mar 23, 2017 at 09:33:19AM +0100, Pino Toscano
wrote:
> On Wednesday, 22 March 2017 16:46:13 CET Richard W.M. Jones wrote:
> > From: "Richard W.M. Jones" <rjones@redhat.com>
> > 
> > Unfortunately libvirt has another bug related to the qemu
> > ssh driver, as described here:
> > 
> > https://bugzilla.redhat.com/show_bug.cgi?id=1434651#c3
> > 
> > Until this bug is fixed we have to require the direct backend to be
> > used for xen+ssh conversions.
> > 
> > This partially reverts commit
ecbf09385033ba0acf14e914927ec81ad20a5308.
> > ---
> >  v2v/input_libvirt_xen_ssh.ml | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/v2v/input_libvirt_xen_ssh.ml
b/v2v/input_libvirt_xen_ssh.ml
> > index 4975eff..a68cdf8 100644
> > --- a/v2v/input_libvirt_xen_ssh.ml
> > +++ b/v2v/input_libvirt_xen_ssh.ml
> > @@ -38,6 +38,9 @@ object
> >      debug "input_libvirt_xen_ssh: source: scheme %s server
%s"
> >            scheme server;
> >  
> > +    if backend_is_libvirt () then (
> > +      error (f_"because of libvirt bug
https://bugzilla.redhat.com/1434651 you must set this environment
variable:\n\nexport LIBGUESTFS_BACKEND=direct\n\nand then rerun the virt-v2v
command.")
> > +    );
> 
> LGTM if you amend the bug number to RHBZ#1140166 in commit log and
> error message.
> 
> Should this also be documented briefly in the manual? I.e. mention that,
> due to libvirt limitations, Xen conversions using the libvirt backend
> will not work, and this the direct backend is needed.
Pushed with the amendments you suggest above.

https://github.com/libguestfs/libguestfs/commit/7cf85ace19231085e514b980bd13b7976e21a242

is required for RHEL 7.4.

Thanks,

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org