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Technical white paper | HP StoreVirtual 4000 Storage
Table 6 provides a working illustration of how to calculate “network transfer rate and time” for a data change rate of 4
GB per hour with an every 4-hour remote snapshot schedule. Meaning the primary volume change rate is 16 GB over a
4-hour period.
Table 6. Remote Copy calculation: 16 GB replication using 10 Mb MPLS interconnect
Conversion description Conversion factor Calculation
Gigabytes to megabytes GB x 1204 = MB 16 GB x 1024 = 16,384 MB
Megabytes to kilobytes MB x 1024 = KB 16,384 MB x 1024 = 16,777,216 KB
Kilobytes to bytes KB x 1024 = bytes 16,777,216 KB x 1024 = 17,179,869,184 bytes
Bytes to bits Bytes x 8 = bits 17,179,869,184 Bytes x 8 = 137,438,953,472 bits
Bits to kilobits Bits/1000 = Kb 137,438,953,472 Bits/1000 = 137,438,953 Kb
Kilobits to megabits Kb/1000 = Mb 137,438,953 Kb/1000 = 137,438 Mb
Megabits per second Mb/network link speed in Mb/s 137,438 Mb / 10 Mb/s = 13743 sec
Seconds to minutes Second/60 = minutes 13743/60 = 229 min
Minutes to hours Minutes/60 = hours 229 min/60 = 3.81 hours < Remote Copy window
Remote Copy schedule is every four hours
Table 7. Remote Copy transfer rate @ dierent network link speeds
Network media Network link speed Remote Copy rate in KB/s Replication time in hours
Fractional T1 256 Kb/s 32 149.1
Fraction T1 768 Kb/s 96 49.7
T1 1.54 Mb/s 193 24.7
Bonded T1 (2) 3.0 Mb/s 386 12.4
Bonded T1 (3) 6.0 Mb/s 722 6.2
Ethernet 10 Mb/s 1,250 3.8
T3 45.0 Mb/s 5,592 51.2 minutes
Fast-Ethernet 100.0 Mb/s 12,500 22.9 minutes
O C-3 155.0 Mb/s 19,375 14.8 minutes
O C-12 622.0 Mb/s 7 7,50 0 3.7 minutes
Gigabit-Ethernet 1000.0 Mb/s 12,5000 2.3 minutes
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