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Re: [openstack-dev][Cinder]Management of Block storage by nova-volume through iSCSI
On Fri, Sep 28, 2012 at 4:37 AM, Ahmed Al-Mehdi <ahmed@xxxxxxxxxx> wrote:
> Who manages LVM VG - "nova-volumes".
The operator is responsible for creating the LVM volume group, from
the physical volumes's available on the system. This options
specifies the name of the volume group that the volume-manager will
use to provision volumes and snapshots. You get an error if it does
> My thinking is nova-volume creates LV
> out of this VG and feeds it into iSCSI Target using utilites - tgt-admin,
> tgt-setup-lun (etc.). This LV is then exported as a block storage by the
> iSCSI Target. This block storage is then attached to / seen by a VM
> instance on the same or another physical host which has iSCSI connection to
> the SCSI Tgt. Would that be correct
Sounds right to me.
> If so, I have a few questions:
> - What if I want to "feed" additional disks/block devices or VGs to
> nova-volume module? How and where would I specify that. Or do I have to
> modify the nova-volume code to handle that. (One solution I can think of is
> to pool the additional storage into the existing VG - nova-volumes.)>
vgextend should do the trick.
> - What if I don't want to feed any VG to nova-volume, but rather want
> nova-volume to call into the iSCSI target to get block storage.
> - I would like to understand the interaction/interface/API of nova-volume
> (Cinder) that calls into iSCSI Target to expose storage or API to storage
> appliance to get block storage. Is this a generic standardized API that
> can call into any type of block storage - iSCSI , FCoE, etcv? If so,
> pointers to API would be highly appreciated.
None of the current drives support this to my knowledge. You would
have to write a custom driver.