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 |