5 – Best Practices
SN0051424-00 B 5
Refer to the attached Timeline for Remote Migration Project.xlsx spreadsheet to
estimate the amount of data that can be transferred weekly based on the available bandwidth and
change rate at the source.
Remote migration projects depend on the available bandwidth, RTT, and change rate for data under
migration. This spreadsheet provides an estimate of how much data can be migrated online remotely
per week, using the available WAN bandwidth and specified change rate. It also indicates a timetable
on when to start migrations. This method assumes that the application cut-over to the destination starts
on Day 6 and Day 7 of the week.
In the spreadsheet, you must enter the following highlighted values:
Dedicated Bandwidth (Mbps) (the bandwidth of the WAN link used to connect the source and
destination in Mbps).
Change Rate for Data Under Migration (%) (the rate at which the source LUN changes).
The calculation is:
((B4/10%)36002485%)/1000
where:
B4 is equal to the dedicated bandwidth of the configuration (whatever is available).
10% is the change of rate for data under migration.
3600 is the number of seconds in an hour (60 seconds per minute 60 minutes per hour).
24 is the number of hours per day.
85% is the percentage of bandwidth efficiency.
Dividing by 1000 gives a result in GB.
The result is the weekly total GB migrated.
In the example depicted in Figure 5-1, you start with 3,305GB of migration on Day 1, 3,342GB of
migration on Day 2, and so on. Assuming that the 500Mbps bandwidth entered is available, the cut-over
to the destination is possible on Day 6 or Day 7.
NOTE:The Timeline for Remote Migration Project.xlsx file is a Microsoft® Excel®
spreadsheet that is attached to this PDF.