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20 PS Series Asynchronous Replication Best Practices and Sizing Guide | BP1012
6.5 Bandwidth effects
Asynchronous replication is affected by the speed of the link between replication partners. When replicating
within the same data center or between buildings, the available bandwidth may be equal to the full speed of
the SAN. In other cases, a slower WAN link may be utilized. Figure 8 shows the effect that network link speed
can have on the time it takes to complete replication.
Effects of WAN speed on time to complete 100GB replication
This shows that the time it takes to replicate 100 GB of data doubles when the network is reduced from 10 Gb
to 1 Gb. Reducing the network link to OC3 causes the replication time to increase to more than 11 times the
speed at 10 Gb. When the network speed reduces to T1 rates, replication time increases to 9480 minutes, or
more than 6.5 days. Clearly, a single T1 network link may not be adequate if large amounts of data need to
be replicated.
8.15
16.23
94.98
325.07
9480.00
1
10
100
1000
10000
10Gb 1Gb OC3
(155 MB/s)
T3
(45 MB/s)
T1
(1.5 MB/s)
Minutes
Network link speed
Time to complete 100GB replication