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We use the Bonnie benchmark [1] to evaluate
performance when writing and reading a large file. To eliminate
caching effects we use a 512MB file, twice the size of main memory. In
our results we also include the performance of FFS and
NFSv3 for completeness.
Figure 5:
Bonnie Sequential Output (Block). DisCFS throughput is
comparable to NFSv2 throughput.
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Figure 6:
Bonnie Sequential Input (Block). DisCFS throughput is
less than 50% of NFSv2 throughput, mostly due to its lack of prefetching.
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Figure 7:
Bonnie Sequential Output (Rewrite). DisCFS throughput
is closer to NFSv2 throughput than for reads, but still suffers from
its lack of prefetching.
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Figure 5 presents results for block writes. The
perfomance of DisCFS is equivalent to that of NFSv2
because the credential related overheads of DisCFS are amortized
over the time of the experiment. Remember that this experiment is on a
single file.
Figure 6 presents results for block reads. We observe
that for read operations DisCFS trails NFSv2 by more than
100%. The reason for this behavior is that NFSv2 prefetches
blocks, an optimization which we have yet to incorporate in the
current implementation of DisCFS.
Finally, in Figure 7 we experiment with the cost of
rewriting blocks. More specifically, in this test Bonnie reads a
block, dirties it, and then writes it back. As expected, the
performance of DisCFS is closer to NFSv2 than in the read
benchmarks, however DisCFS still suffers from its lack of
prefetching.
Next: Macro-benchmarks
Up: Experimental Evaluation
Previous: Experimental Evaluation
Stefan Miltchev
4/8/2003