In the era of explosive information, storage subsystem is becoming more and more important in our daily life and commercial markets. Because more and more data are recorded in the digital form and stored in the storage device, an intelligent mechanism is required to make the management of the digital data and storage devices more eficiently rather than simply keep increasing more storage equipment into a system. The concept of storage virtualization was introduced to solve this problem, by aggregating all the physical devices into a single virtual storage device and hidding the complexity of underlying block devices. Through this virtual layer, users can dynamically allocate and resize their virtual storage device to satisfy their need, and they can also use the methods provided by the virtual layer to organize data more efficiently. Linux Logical Volume Manager 2 (LVM2) is an implementation of storage virtualization on the Linux operation system. It includes three components: the kernel-space devicemapper, the user-space device-mapper support library (libdevmapper), and the user-space LVM2 toolset. This thesis will focus on the kernel-space device-mapper, which provides virtualization mechanism for user-space logical volume manager. The organization of this thesis is composed of : (1) Introduce novel technologies in the recent years, (2) Provide an advanced document about the internals of device-mapper, (3) Try optimizing the mapping table algorithm, and (4) Evaluate the performance of device-mapper.