VMware vSphere Fault Tolerance 4 - Manual (Page 8)

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Figure 4. SPECjbb2005 Performance
0
20
40
60
80
100
120
FT Disabled
FT Enabled
SPECjbb2005
Rela
tiv
e per
formanc
e (%)
RHEL 5 64-bit, 4GB
FT traffic:
1.4 Mbits/sec
3.2. Kernel Compile
This experiment shows the time taken to do kernel compile, which is both CPU and MMU intensive workload due to forking of many
parallel processes. As with the previous experiment, CPU is 100 percent utilized and thus FT performance is dependent on how well
the secondary can keep pace with the primary. This workload does some disk reads and writes, but generates no network traffic.
Besides timer interrupt events, the FT logging traffic includes the disk reads. As seen in theFigure 5, the performance overhead of
enabling FT was very small.
Figure 5. Kernel Compilation Performance
0
50
100
150
200
250
300
350
FT Disabled
FT Enabled
Kernel Compile
(lower is better)
Sec
onds
SLES 10 32-bit, 512MB
FT traffic:
3 Mbits/sec