[libvirt-users] Ang: Re: Ang: Re: Ang: Re: attaching storage pool error

[Johan Kragsterman]

Hi!



-----Yuan Dan <dyuan at redhat.com> skrev: -----
Till: Johan Kragsterman <johan.kragsterman at capvert.se>
Från: Yuan Dan <dyuan at redhat.com>
Datum: 2016-08-24 10:22
Kopia: libvirt-users at redhat.com
Ärende: Re: [libvirt-users] Ang: Re: Ang: Re: attaching storage pool error


----- Original Message -----
> 
> Hi and thanks for your important input,Dan!
> 
> 
> > > 
> > > 
> > > System centos7, system default libvirt version.
> > > 
> > > I've succeeded to create an npiv storage pool, which I could start
> > > without
> > > problems. Though I couldn't attach it to the vm, it throwed errors when
> > > trying. I want to boot from it, so I need it working from start. I read
> > > one
> > > of Daniel Berrange's old(2010) blogs about attaching an iScsi pool, and
> > > draw
> > > my conclusions from that. Other documentation I haven't found. Someone
> > > can
> > > point me to a more recent documentation of this?
> > > 
> > > Are there other mailing list in the libvirt/KVM communities that are more
> > > focused on storage? I'd like to know about these, if so, since I'm a
> > > storage
> > > guy, and fiddle around a lot with these things...
> > > 
> > > There are quite a few things I'd like to know about, that I doubt this
> > > list
> > > cares about, or have knowledge about, like multipath devices/pools,
> > > virtio-scsi in combination with npiv-storagepool, etc.
 
> 
> 
> 
> 
> As I described above, I created an npiv pool for my FC backend. I'd also like
> to get scsi pass through, which seems to be possible only if I use
> "device=lun". Can I NOT use "device=lun", and then obviously NOT get "scsi
> pass through", if I use an npiv storage pool? Is the only way to get "scsi
> pass through" to NOT use a storage pool, but instead use the host lun's?
> 
> 
> What do you think about this?:
> 
> <disk type='volume' device='disk'>
>   <driver name='qemu' type='raw'/>
>   <source pool='vhbapool_host8' volume='unit:0:0:1'/>
>   <target dev='hda' bus='ide'/>
> </disk>
> 
> 
> But I'd prefer to be able to use something like this instead:
> 
> 
> 
> <disk type='volume' device='lun'>
>   <driver name='qemu' type='raw'/>
>   <source pool='vhbapool_host8' volume='unit:0:0:1'/>
>   <target dev='vda' bus='scsi'/>
> </disk>
> 
> But that might not be possible...?
> 

No need to prepare the pool for the following 2 usage.
Is it satisfied your requirement ?

http://libvirt.org/formatdomain.html#elementsHostDevSubsys

    <hostdev mode='subsystem' type='scsi'>
      <source>
        <adapter name='scsi_host0'/>
        <address bus='0' target='0' unit='0'/>
      </source>
      <readonly/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </hostdev>


  <disk type='block' device='disk'>
     <driver name='qemu' type='raw'/>
     <source dev='/dev/disk/by-path/pci-0000\:04\:00.1-fc-0x203400a0b85ad1d7-lun-0'/>
     <target dev='sda' bus='scsi'/>
  </disk>





Ahh, the "<hostdev mode='subsystem' type='scsi'>", I didn't understand that possibility until now...hmmm, seems useful. Does that include the multipath ability, as I mentioned in my previous mail?

And if so, how would I handle it in the guest? Seems impossible le to use: "<target dev='sda' bus='scsi'/>"


Regards Johan




Thanks
Dan

> 
> 
> Regards Johan
> 
> > 
> > > 
> > > Rgrds Johan
> > > 
> > > 
> > > _______________________________________________
> > > libvirt-users mailing list
> > > libvirt-users at redhat.com
> > > https://www.redhat.com/mailman/listinfo/libvirt-users
> > > 
> > > 
> > > 
> > 
> > 
> > 
> > 
> 
> 
> 
> 
> _______________________________________________
> libvirt-users mailing list
> libvirt-users at redhat.com
> https://www.redhat.com/mailman/listinfo/libvirt-users
> 
> 
>