智慧型手機檔案系統設計

智慧型手機是近年來最重要的科技之一，但為了達到攜帶性及省電的因素，智慧型手機只有受限制的運算能力以及較小的存儲空間。因為手機上的儲存空間過小，我們無法將所有的個人資料儲存在手機上。我們設計了一個行動運算雲叫做”Nexus”，Nexus是用來提供給智慧型手機更好的方變性。Nexus可以提供給使用者很大的虛擬儲存空間來儲存所有的個人資料。並且透過快取的設計，提供使用者在網路狀況不好的時候仍然有機會獲得良好的使用者經驗，另外也可以提供使用者離線作業的服務。

關鍵字

智慧型手機；雲端儲存服務；快取；離線作業

並列摘要

Smartphone has been one of most important technologies in recent years. However, smartphone only has a limited computing capability and a relatively small storage, because a smartphone must conserve power in order to achieve longer operation time. Due to its limited storage space it is impossible to store all the personal data into a smartphone. In addition, the CPU of a smartphone runs at relatively low clock rate so we cannot run resource demanding application because of the limited computing power. We designed a ﬁle system for smartphone called NexusFS to overcome the inconveniences while using a smartphone. NexusFS can provide smartphone user Tera bytes of cloud virtual storage, which users can store all their personal data. NexusFS provides a cache mechanism on the smartphone. The NexusFS caches the user recently used ﬁles for user which gives good user experiences in accessing ﬁle in the cloud under unstable network environment such as 3G network, and supports disconnected operations on the mobile phone. The smartphone user can edit ﬁles on the smartphone transparently even without network accessing. NexusFS also provides version controlling mechanism which enable users to cooperate on the shared ﬁles on the cloud. With NexusFS, the smartphone users can access the ﬁles on the cloud more efﬁciently, and the smartphone application developers can use the cloud storage resource as the POSIX [1] standard local ﬁle system without using special API, which enables general applications on the smartphone to use the cloud storage resource without modifying. Smartphone application developers can concentrate on development of the application without concerning how to connect to a cloud storage service.