[Qemu-devel] drive_mirror to nbd with tls ?

[Qemu-devel] drive_mirror to nbd with tls ?

[Alexandre DERUMIER]

Hi,

I'm currently trying to implemented drive_mirror to nbd with tls.

It's working fine without tls,  but with tls enabled on target,

I don't known how to pass tls-creds to drive_mirror nbd uri ?  

I don't see any option in nbd uri schema.

Currently, I have this error "TLS negotiation required before option 3" with calling drive_mirror to nbd.

Any idea ?

Regards,

Alexandre Derumier

Re: [Qemu-devel] drive_mirror to nbd with tls ?

[Eric Blake]

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On 01/04/2017 01:34 PM, Alexandre DERUMIER wrote:
> Hi,
> 
> I'm currently trying to implemented drive_mirror to nbd with tls.
> 
> It's working fine without tls,  but with tls enabled on target,
> 
> I don't known how to pass tls-creds to drive_mirror nbd uri ?  

Unfortunately, drive-mirror is not set up for structured specifications
(it can only take a URI), and at the same time, NBD requires the use of
structured specification (along the lines of 'blockdev-add' in qemu 2.8)
to specify TLS parameters.  In other words, it's intentional that there
is no NBD URI that you can write that allows TLS.  So for any earlier
versions of qemu, you're stuck.

But for qemu 2.8, we have the new blockdev-mirror (well, that command
was added in qemu 2.6, but you couldn't use NBD through blockdev-add
back then); so the correct way is to create a BDS that targets the NBD
server using 'blockdev-add' to specify the NBD parameters, then use
blockdev-mirror to mirror to that BDS.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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