libvirt users - Aug 2018 - Mount URL as cdrom/iso KVM/QEMU

Hi Folks,


According to the examples in http://libvirt.org/formatdomain.html#elementsDisks
it should be possible to mount an iso /url as a cdrom, the example given is:


</disk>
  <disk type='network' device='cdrom'>
    <driver name='qemu' type='raw'/>
    <source protocol="http" name="url_path">
      <host name="hostname" port="80"/>
    </source>
    <target dev='hde' bus='ide' tray='open'/>
    <readonly/>
  </disk>


I am unable to get this to work at all and wondered if I am just missing
something obvious:

Boot failed: Could not read from CDROM (code 0003)

Actual XML in use snippet:

<disk type='network' device='cdrom'>
    <driver name='qemu' type='raw'/>
    <source protocol="http"
name="/debian-cd/current/amd64/iso-cd/debian-9.5.0-amd64-netinst.iso">
      <host name="mirror.bytemark.co.uk" port="80"/>
    </source>
    <target dev='hdb' bus='ide' tray='open'/>
    <readonly/>
  </disk>
libvirtd (libvirt) 3.9.0 QEMU emulator version 2.10.0

Is anyone able to offer any assistance or tips?

I have tried putting the complete path including fqdn in the url_path as well,
with and without http://

Many Thanks.

Anthony.

On Wed, Aug 08, 2018 at 12:11:22PM +0000, Inception Hosting
wrote:
> Hi Folks,
> 
> 
> According to the examples in
http://libvirt.org/formatdomain.html#elementsDisks it should be possible to
mount an iso /url as a cdrom, the example given is:
> 
> 
> </disk>
>   <disk type='network' device='cdrom'>
>     <driver name='qemu' type='raw'/>
>     <source protocol="http" name="url_path">
>       <host name="hostname" port="80"/>
>     </source>
>     <target dev='hde' bus='ide' tray='open'/>
>     <readonly/>
>   </disk>
> 
> 
> I am unable to get this to work at all and wondered if I am just missing
something obvious:
> 
> Boot failed: Could not read from CDROM (code 0003)
> 
> Actual XML in use snippet:
> 
> <disk type='network' device='cdrom'>
>     <driver name='qemu' type='raw'/>
>     <source protocol="http"
name="/debian-cd/current/amd64/iso-cd/debian-9.5.0-amd64-netinst.iso">
>       <host name="mirror.bytemark.co.uk"
port="80"/>
>     </source>
>     <target dev='hdb' bus='ide' tray='open'/>
>     <readonly/>
>   </disk>
> libvirtd (libvirt) 3.9.0 QEMU emulator version 2.10.0
> 
> Is anyone able to offer any assistance or tips?
This XML looks reasonable to me. There have been bugs in QEMU's curl driver
though, so it might be worth retesting with latest QEMU 2.12.0, or even the
3.0.0-rc4 release from yesterday, to check if its a bug in that version of
QEMU


Regards,
Daniel
-- 
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ср, 8 авг. 2018 г. в 15:11, Inception Hosting
<inbox@inceptionhosting.com>:
>
> Hi Folks,
>
>
> According to the examples in
http://libvirt.org/formatdomain.html#elementsDisks it should be possible to
mount an iso /url as a cdrom, the example given is:
>
Usually such errors because url not available from host system. Can
you try curl this host and address from node?


-- 
Vasiliy Tolstov,
e-mail: v.tolstov@selfip.ru

Resolved this morning,


the issue is that the qemu-kvm-ev rpm's released by centos have not been
compiled with curl support, I rebuild it myself from source with curl support
and it works fine now.


Thanks you for your input everyone.

________________________________
From: Vasiliy Tolstov <v.tolstov@selfip.ru>
Sent: 09 August 2018 10:32:07
To: Inception Hosting
Cc: libvirt-users@redhat.com
Subject: Re: [libvirt-users] Mount URL as cdrom/iso KVM/QEMU

ср, 8 авг. 2018 г. в 15:11, Inception Hosting
<inbox@inceptionhosting.com>:
>
> Hi Folks,
>
>
> According to the examples in
http://libvirt.org/formatdomain.html#elementsDisks it should be possible to
mount an iso /url as a cdrom, the example given is:
>
Usually such errors because url not available from host system. Can
you try curl this host and address from node?


--
Vasiliy Tolstov,
e-mail: v.tolstov@selfip.ru