4:47 p.m.
Hello.
I'm trying to use ssh tunnel for remote hypervisor access. However, I'm
can't make it working...
[guillaume@oberkampf ~]$ LC_ALL=C virsh --connect
xen+ssh://root@acacia.futurs.inria.fr list --all
libvir: error : could not connect to xen://
error: failed to connect to the hypervisor
error: no valid connection
On the remote host:
[root@acacia ~]# libvirtd --verbose
libvir: error : could not connect to xen://
It seems the error lies between libvirtd and the local hypervisor. And
indeed, local usage of virsh with xen:// URLs fail:
[root@acacia ~]# LC_ALL=C virsh -c xen:// list
libvir: error : could not connect to xen://
error: failed to connect to the hypervisor
error: no valid connection
Using xen:///, instead of xen://, as explained at
http://libvirt.org/uri.html, is OK, despite a few error messages:
[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
libvir: Remote error : No such file or directory
libvir: warning : Failed to find the network: Is the daemon running ?
Id Name State
----------------------------------
0 Domain-0 running
1 barman blocked
2 cocktail blocked
3 mojito blocked
From the documentation, it seems xen:// transport implies TLS, and
requires an host name, so it is quite normal it fails here (I didn't
generated any certificate). But how can I force libvirtd to use xen:///
transport then ? I don't see anything related in libvirt configuration
documentation at http://libvirt.org/remote.html ? Neither about how to
configure it for listening on unix transport, as explained in svn+ssh
transport requirements on the same page (but I presume it is the default) ?
Also, from where does those error and warning come ?
[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
libvir: Remote error : No such file or directory
libvir: warning : Failed to find the network: Is the daemon running ?
[..]
I'm using libvirt 0.3.2 on mandriva 2007.1, with xen 3.1.0.
--
Guillaume Rousse
Moyens Informatiques - INRIA Futurs
Tel: 01 69 35 69 62
5:06 p.m.
On Wed, Sep 26, 2007 at 11:47:40PM +0200, Guillaume Rousse wrote:
Hello.
I'm trying to use ssh tunnel for remote hypervisor access. However, I'm
can't make it working...
[guillaume@oberkampf ~]$ LC_ALL=C virsh --connect
xen+ssh://root@acacia.futurs.inria.fr list --all
You are missing a trailing '/' on the URI - when strip the hostname to
make the remote uri, we end up with xen:// which is rejected by libxml's
URI parser. Simply add a '/' after the hostname and you should be fine.
It is rather annoying that libxml's parser rejects uris only ending in
two /, but not three. We should probably automatically add an extra
trailing / if we find we only have two, because its a common mistake.
libvir: error : could not connect to xen://
error: failed to connect to the hypervisor
error: no valid connection
On the remote host:
[root@acacia ~]# libvirtd --verbose
libvir: error : could not connect to xen://
It seems the error lies between libvirtd and the local hypervisor. And
indeed, local usage of virsh with xen:// URLs fail:
[root@acacia ~]# LC_ALL=C virsh -c xen:// list
Yep, xen:// is not a valid URI for libxml parser.
libvir: error : could not connect to xen://
error: failed to connect to the hypervisor
error: no valid connection
Using xen:///, instead of xen://, as explained at
http://libvirt.org/uri.html, is OK, despite a few error messages:
[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
libvir: Remote error : No such file or directory
libvir: warning : Failed to find the network: Is the daemon running ?
That is harmless unless you want to use the networking APIs.
From the documentation, it seems xen:// transport implies TLS, and
requires an host name, so it is quite normal it fails here (I didn't
generated any certificate). But how can I force libvirtd to use xen:///
transport then ? I don't see anything related in libvirt configuration
documentation at http://libvirt.org/remote.html ? Neither about how to
configure it for listening on unix transport, as explained in svn+ssh
transport requirements on the same page (but I presume it is the default) ?
The daemon libvirtd will always listen for UNIX socket connections. You
have to explicitly turn on TCP support, after having setup certificates.
If using SSH, then we simply tunnel to the UNIX socket over SSH so all
you need do is start the libvirtd daemon on the remote host.
Also, from where does those error and warning come ?
[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
libvir: Remote error : No such file or directory
libvir: warning : Failed to find the network: Is the daemon running ?
That is a sign that the libvirtd daemon is notrunning on the host in
questions.
Regards,
Dan.
--
|=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=|
|=- Perl modules: http://search.cpan.org/~danberr/ -=|
|=- Projects: http://freshmeat.net/~danielpb/ -=|
|=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|
2:28 a.m.
Daniel P. Berrange a écrit :
On Wed, Sep 26, 2007 at 11:47:40PM +0200, Guillaume Rousse wrote:
> Hello.
>
> I'm trying to use ssh tunnel for remote hypervisor access. However, I'm
> can't make it working...
>
> [guillaume@oberkampf ~]$ LC_ALL=C virsh --connect
> xen+ssh://root@acacia.futurs.inria.fr list --all
You are missing a trailing '/' on the URI - when strip the hostname to
make the remote uri, we end up with xen:// which is rejected by libxml's
URI parser. Simply add a '/' after the hostname and you should be fine.
Ahhhhhhh.... Thanks a lot.
It is rather annoying that libxml's parser rejects uris only
ending in
two /, but not three. We should probably automatically add an extra
trailing / if we find we only have two, because its a common mistake.
It would be
more idiots-proof :)
[..]
> From the documentation, it seems xen:// transport implies TLS,
and
> requires an host name, so it is quite normal it fails here (I didn't
> generated any certificate). But how can I force libvirtd to use xen:///
> transport then ? I don't see anything related in libvirt configuration
> documentation at http://libvirt.org/remote.html ? Neither about how to
> configure it for listening on unix transport, as explained in svn+ssh
> transport requirements on the same page (but I presume it is the default) ?
The daemon libvirtd will always listen for UNIX socket connections. You
have to explicitly turn on TCP support, after having setup certificates.
If using SSH, then we simply tunnel to the UNIX socket over SSH so all
you need do is start the libvirtd daemon on the remote host.
Can you rephrase the
documentation a little bit then ? It seems to imply
you have to do some additional libvirtd configuration for ssh transport
usage.
> Also, from where does those error and warning come ?
> [root@acacia ~]# LC_ALL=C virsh -c xen:/// list
> libvir: Remote error : No such file or directory
> libvir: warning : Failed to find the network: Is the daemon running ?
That is a sign that the libvirtd daemon is notrunning on the host in
questions.
However it is running:
[root@acacia ~]# service libvirtd start
Lancement du service libvirtd : [ OK ]
[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
libvir: Remote error : No such file or directory
libvir: warning : Failed to find the network: Is the daemon running ?
Id Name State
----------------------------------
0 Domain-0 running
1 barman blocked
2 cocktail blocked
3 mojito blocked
[root@acacia ~]# service libvirtd status
libvirtd (pid 19102) est en cours d'exécution...
--
Guillaume Rousse
Moyens Informatiques - INRIA Futurs
Tel: 01 69 35 69 62
4:37 a.m.
Guillaume Rousse wrote:
Daniel P. Berrange a écrit :
> The daemon libvirtd will always listen for UNIX socket connections. You
> have to explicitly turn on TCP support, after having setup certificates.
> If using SSH, then we simply tunnel to the UNIX socket over SSH so all
> you need do is start the libvirtd daemon on the remote host.
Can you rephrase the documentation a little bit then ? It seems to imply
you have to do some additional libvirtd configuration for ssh transport
usage.
Suggested change to the documentation attached.
>> Also, from where does those error and warning come ?
>> [root@acacia ~]# LC_ALL=C virsh -c xen:/// list
>> libvir: Remote error : No such file or directory
>> libvir: warning : Failed to find the network: Is the daemon running ?
> That is a sign that the libvirtd daemon is notrunning on the host in
> questions.
Well sometimes, but also it can be a sign that virsh is trying to use
the wrong Unix socket, or that the Unix socket has the wrong permissions
or is otherwise inaccessible. Try:
/usr/sbin/libvirtd --help
(which should print out all the paths expected by libvirtd) and:
strace virsh -c xen:/// list
which should tell you what socket virsh is trying to connect on.
In any case this warning can be ignored unless you want to manipulate
networks.
Rich.
--
Emerging Technologies, Red Hat - http://et.redhat.com/~rjones/
Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod
Street, Windsor, Berkshire, SL4 1TE, United Kingdom. Registered in
England and Wales under Company Registration No. 03798903
7:48 a.m.
On Thu, Sep 27, 2007 at 10:37:47AM +0100, Richard W.M. Jones wrote:
Guillaume Rousse wrote:
>Daniel P. Berrange a écrit :
>>The daemon libvirtd will always listen for UNIX socket connections. You
>>have to explicitly turn on TCP support, after having setup certificates.
>>If using SSH, then we simply tunnel to the UNIX socket over SSH so all
>>you need do is start the libvirtd daemon on the remote host.
>Can you rephrase the documentation a little bit then ? It seems to imply
>you have to do some additional libvirtd configuration for ssh transport
>usage.
Suggested change to the documentation attached.
>>>Also, from where does those error and warning come ?
>>>[root@acacia ~]# LC_ALL=C virsh -c xen:/// list
>>>libvir: Remote error : No such file or directory
>>>libvir: warning : Failed to find the network: Is the daemon running ?
>>That is a sign that the libvirtd daemon is notrunning on the host in
>>questions.
Well sometimes, but also it can be a sign that virsh is trying to use
the wrong Unix socket, or that the Unix socket has the wrong permissions
or is otherwise inaccessible. Try:
Actually on my F8 test machine I saw this yesterday, but I rebooted the
machine to another OS in the meantime.
/usr/sbin/libvirtd --help
(which should print out all the paths expected by libvirtd) and:
strace virsh -c xen:/// list
which should tell you what socket virsh is trying to connect on.
In any case this warning can be ignored unless you want to manipulate
networks.
Still if this occurs on a default installation, it would be great to avoid
it, sorry I didn't took the time to chase it yesterday :-\
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard(a)redhat.com | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
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4 comments
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participants (4)
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Daniel P. Berrange -
Daniel Veillard -
Guillaume Rousse -
Richard W.M. Jones