Volume Managers in Linux

A volume manager is a subsystem for on-line disk storage management which has become a de-facto standard across UNIX implementations and is a serious enabler for Linux in the enterprise computing area. It adds an additional layer between the physical peripherals and the I/O interface in the kernel to present a logical view of disks, unlike current partition schemes where disks are divided into fixed-size sections.

In addition to providing a logical level of management, a volume manager will often implement one or more levels of software RAID to improve performance or reliability. Advanced logical management tools and software RAID are the specialties of the Logical Volume Manager (LVM) and Multiple Devices (MD) drivers respectively. These are the two most widely used Linux volume managers today.

This paper describes the current technologies available in Linux and new work in the area of volume management.