Stephen A. Fridella

Storage virtualization using a block-device file system

The design and organization of modern file systems has been traditionally driven by practical considerations related to the physical properties of computer disks Storage virtualization makes such considerations largely irrelevant, and file-system designs based on them perform sub-optimally in a virtual storage environment. One important example of this phenomenon is the relationship between disk seek times and the placement and organization of file system meta-data. In this paper we show that traditional approaches to organizing meta-data in file systems are closely related to assumptions about the physical properties of disks and that for this reason traditional file systems fail to materialize the full benefits of storage virtualization. We go on to propose a different file system organization of data and meta-data designed to exploit the power of virtualized storage.