Migrating Datasource is Source System Specific or not?

Hi,

i need some information about Datasource migration form 3.x to 7.x

I have a following landscape:

One BW System(7.01) and 2 Backend Systems(System A and System B).

We load data with Datasource 2LIS_02_CGR from System A with 3.x technology.

We want to load data with the same DS from System B with 7.x technology. Therefore the DS should be migrated from 3.x to 7.x.

If I migrate the DS, what happens with the datastaging from System A(Vers. 3.x)? I should migrate the whole Datastaging or the migration is source System specific and i have nothing to do with the datastaging from System A?

Thanks,

Balazs