Expandable NAS (X-NAS) and Its Autonomic File Redistribution Policy
Shinichi Kawamoto, Atsushi Ebata, Jun Okitsu, Yoshiko Yasuda, Tatsuo Higuchi, Naoki Hamanaka · 2003
To achieve both reasonable cost of ownership and capacity scalability in office use NAS, we propose an expandable network attached storage (X-NAS) which is a cluster system of two or more entry-level NASes and offers an unified file system view. In such cluster system, the file size variation causes disk usage unbalancing problem. When one elemental NAS is filled up to its capacity, users can not write additional files into the system, even if the other elemental NASes have enough space. We solved this problem by adding an autonomic file redistribution policy to X-NAS. Experimental results indicate that this policy can solve disk usage unbalancing problem.