We evaluate the following four combinations of file systems and simulated disks (shown in Figure 5): a UFS on a regular disk, a UFS on a Virtual Log Disk (VLD), an LFS on a regular disk, and an LFS on a VLD. Although we do recognize that a complete evaluation of the VLFS would require a complete implementation of VLFS, in this paper, we take the first step of deducing the behavior of VLFS by examining the file systems running on the VLD.
Two host machines are used: one is a 50 Mhz SUN SPARCstation-10, which is equipped with 64 MB of memory and runs Solaris 2.6; the other is a similarly configured UltraSPARC-170 workstation that runs at 167 Mhz. The SPARCstation-10 supports both 4 KB and 8 KB file blocks while the UltraSPARC-170 only supports 8 KB file blocks. Because our focus is small write performance, we run our experiments on the SPARCstation-10 unless explicitly stated to be otherwise. We perform some additional experiments on the UltraSPARC-170 only to study the impact of host processing speed. We next briefly describe each of the disk modules and file systems shown in Figure 5.
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Figure 5: Architecture of the experimental
platform. |