Segment Utilization Distribution

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Segment Utilization Distribution

In order to provide insights into understanding why WOLF significantly outperforms the LFS, we also compared the segment utilization distributions of WOLF and LFS. Segment utilization is calculated by the total live bytes in the segment divided by the size of this segment.

Figure 7 shows the distribution of segment utilizations under the four real-world traces. We can see the obvious bimodal segment distribution in WOLF when compared to the LFS. Results for other workloads are similar. The nice bimodal distribution is the key to the performance advantage of WOLF over the LFS.

**Figure 7:** Segment Utilization versus Fraction of Segments. *Disk utilization is 80%.*
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Jun Wang 2001-10-31