[sheepdog] [Sheepdog]Openstack support sheepdog matters?

[Liu Yuan]

On 01/18/2013 07:38 PM, harryxiyou wrote:
> aybe i am self-contradictory. Therefore,  i just wanna contrast their(ISCSI and
> QEMU/Libvirt) realization differences so i also need the SheepdogISCSIDriver.
> What's more, i also wanna know their pros/cons to choose a better way for me.

I haven't yet set up Openstack with a success, but I think iSCSI and
QEMU/libvirt(which can speak Sheepdog protocol to manipulate virtual
volumes) is two different software stacks. They are only correlated as
far as we speak of Openstack's block storage. I have no idea how iSCSI
is implemented in Openstack, but I guess it makes use of existing
open-iscsi as its client side interface, which talks to iSCSI server
such as TGT target. So for sheepdog, I think we only need to retrofit
the old un-merged bs_sheepdog.c in TGT project to a full working state.
Then we can store volumes directly into Sheepdog cluster over iSCSI
protocol.

As for performance, I think using QEMU/Libvirt will give us better
performance since there is no extra iSCSI component in the IO path.

Thanks,
Yuan