V.V. Das, E. Ariwa, and S.B. Rahayu (Eds.): SPIT 2011, LNICST 62, pp. 151–156, 2012. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2012 Error Recovery Mechanism for iSCSI Protocol Based Mobile NAS Cluster System Shaikh Muhammad Allayear 1 , Sung Soon Park 2 , Md. Nawab Yousuf Ali 3 , and Ullah Mohammad Hasmat 4 1,2,3,4 Dept of Computer Science and Engineering 1,3 East West University, Bangladesh 2,4 Anyang University, Korea {allayear,nawab}@ewubd.edu, {sspark,raju}@anyang.ac.kr Abstract. In this paper, we proposed an error recovery module for iSCSI protocol based NAS (Network Attached Storage) system in wireless network environment, which ensures reliability and efficiency data transmission. Keywords: iSCSI Protocol, Network Storage, wireless network. 1 Introduction A NAS system is usually a specially designed device providing clients with files on a LAN; it is widely used to bridge the interoperability gap with many advantages.However, NAS supports only file I/O protocol such as NFS and CIFS, block-level storage applications are not available on NAS with the performance of NFS and CIFS is only a fraction of the exported storage system. To this day, they continue to have limited network, CPU, memory, and disk I/O resources due to their single server design, which binds one network endpoint to all files in a file system.Now, the iSCSI storage has emerged. iSCSI is an Internet Protocol-based storage standard for linking data storage facilities, and presents storage to servers as disk targets[1], which, from the perspective of the application, appear to be storage attached locally to the server. It presents storage space as virtual block-level devices, operating systems and applications have the ability to put their own file systems on them, which is something not possible with NAS.In current age mobile appliances are going to be used in more area as the time goes by. Due to their mobility, they should be small and use a flash memory to store the data. So it is very difficult to store large data and install large software [2],[3],[4],[5],[6],[7].To alleviate these problems and access mass storage we developed MNAS [6], an iSCSI based NAS Cluster system, for providing the allocation of a mass storage space to each mobile client through networks. The system offers to its users the possibility of keeping large size of data and database in a secure and safe space. But in wireless environment data may losses due to bad channel characteristics, interference or intermittent connectivity due to handoffs (mobile appliance). ISCSI over TCP performance in such networks suffers