[Users] Will this two node concept scale and work?

Hello List, my aim is to host multiple VMs which are redundant and are high available. It should also scale well. I think usually people just buy a fat iSCSI Storage and attach this. In my case it should scale well from very small nodes to big ones. Therefore an iSCSI Target will bring a lot of overhead (10GBit Links and two Paths, and really i should have a 2nd Hot Standby SAN, too). This makes scalability very hard. This post is also not meant to be a iscsi discussion. Since oVirt does not support DRBD out of the box i came up with my own concept: http://oi62.tinypic.com/2550xg5.jpg As far as i can tell i have the following advantages: -------------------------------------------------------------------- - i can start with two simple cheap nodes - i could add more disks to my nodes. Maybe even a SSD as a dedicated drbdresource. - i can connect the two nodes directly to each other with bonding or infiniband. i dont need a switch or something between it. Downside: --------------- - i always need two nodes (as a couple) Will this setup work for me. So far i think i will be quite happy with it. Since the DRBD Resources are shared in dual primary mode i am not sure if ovirt can handle it. It is not allowed to write to a vm disk at the same time. The Concept of Linbit ( http://www.linbit.com/en/company/news/333-high-available-virtualization-a...) seems to much of an overhead with the iSCSI Layer and pacemaker setup. Its just too much for such a simple task. Please tell me that this concept is great and will work and scale well. Otherwise i am also thankful for any hints or critical ideas. Thanks a lot, Mario