Re: [libvirt] Re: [Patch v0.4] iSCSI Multi-IQN (Libvirt Support)
On Wed, Nov 18, 2009 at 04:01:53PM +0530, Shyam_Iyer(a)Dell.com wrote:
> -----Original Message-----
> From: Daniel P. Berrange [mailto:berrange@redhat.com]
> Sent: Wednesday, November 18, 2009 3:50 PM
> To: Iyer, Shyam
> Cc: dallan(a)redhat.com; Bellad, Sudhir; libvir-list(a)redhat.com; Domsch,
> Matt; KM, Paniraja
> Subject: Re: [libvirt] Re: [Patch v0.4] iSCSI Multi-IQN (Libvirt
> Support)
>
> On Wed, Nov 18, 2009 at 01:53:50AM +0530, Shyam_Iyer(a)Dell.com wrote:
> > Iscsiadm's -I parameter takes iface name as the parameter value and
> not
> > the iqn name.
> >
> > So I believe this approach could be taken -
> >
> > 1) Get the iqn for the corresponding iface name using the following
> > command
> > #iscsiadm -m iface
> >
> > Example output:
> >
> > [root@localhost libvirt-0.7.1-15-org]# iscsiadm -m iface
> > default tcp,default,default,unknown
> > iser iser,default,default,unknown
> > bnx2i bnx2i,default,default,unknown
> > iface1 tcp,default,default,iqn.1994-05.com.fedora:iqnBellad
> > iface3 tcp,default,default,iqn.dell
> > iface0 tcp,unknown,unknown,iqn.1994-05.com.fedora:iqnSudhir
>
> Ah, so where does this mapping come from ? Does the administrator have
> to
> create the mapping between interfaces & iqns, or is this totally
> automatic
> somehow ?
>
Today the iface file is created by by iscsi administrators using either
of the following methods
1) By hand by editing the iface parameters in
/var/lib/iscsi/ifaces/<iface_file>
Iface.iscsi_ifacename = <iface name>
Iface.net_ifacename = <default, eth0 etc>
Iface.hwaddress = <default, mac address etc>
Iface.transport_name = <tcp, bnx2i etc>
Iface.initiatorname = <iqn name>
This approach isn't really useful for us, since libvirt API is intended to
be usable remotely without any administrator login.
2) By using iscsiadm commands like the following
# iscsiadm -m iface -I <iface_name> -o new
# iscsiadm -m iface -I iface1 --op=update -n iface.initiatorname -v
<iqnname>
In that case, why don't we make libvirt automatically set things up this
way whenever it sees the IQN in the XML file.
We don't change the default initiatorname with libvirt/virt
manager
today right ? So, we haven't added any apis to manage the iface file
name using libvirt as such.
But if required by virt-manager(to create a single window of management)
the iface file could be constructed using libvirt apis that call the
iscsiadm commands detailed in method 2)
We don't need to add any new APIs for this - just automatically add the
mapping whenever logging into a target with a IQN that we don't already
know about
Regards,
Daniel
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