Nowadays, mobile devices have become the necessities of everyday life. However, users may notice that after a long period of usage, mobile devices will start experiencing sluggish response. In this paper, by conducting an empirical study of filesystem fragmentation on several aged mobile devices, we found that: 1) Files may suffer from severe fragmentation, and database files are among the most severely fragmented files; 2) Filesystem fragmentation does affect the performance of mobile devices, and the impact varies from devices to devices. Conventional defragmentation schemes do not work well on mobile devices because they do not consider the characteristics specific to mobile storage. Two pilot solutions were then suggested to enhance file defragmentation for mobile devices.