Because both the regular disk and the VLD export the standard device driver interface, we can run the Solaris UFS (subsequently also labeled as UFS) unmodified on these disks. We configure UFS with a block size of 4 KB and a fragment size of 1 KB. Like most other Unix file systems, the Solaris UFS updates metadata synchronously while the user can specify whether the data writes are synchronous. It also performs prefetching after several sequential reads are detected.