Cloud computing is the dominating paradigm in distributed computing. The most popular open source cloud solutions support different type of storage subsystems, because of the different needs of the deployed services (in terms of performance, flexibility, cost-effectiveness). In this paper, we investigate the supported standard and open source storage types and create a classification. We point out that the Internet Small Computer System Interface (iSCSI) based block level storage can be used for I/O intensive services currently. However, the ATA-over-Ethernet (AoE) protocol uses fewer layers and operates on lower level which makes it more lightweight and faster than iSCSI. Therefore, we proposed an architecture for AoE based storage support in OpenNebula cloud. The novel storage solution was implemented and the performance evaluation shows that the I/O throughput of the AoE based storage is better (32.5-61.5%) compared to the prior iSCSI based storage and the new storage solution needs less CPU time (41.37%) to provide the same services.