can we move the devices from a SRDF DG to SRDF CG without any impact to the replication?

Yes, you may place devices under CG control from a DG without impacting replication. CG's and DG's are containers to group devices for the purpose of controlling and inquiring on them as a whole (or in part). Modifying the container (CG or DG) does not affect replication because no control operation is being carried out. In other words, replication will only be affected by your intentional entering a control command (well, apart from a communications issue between the arrays).

Thanks Jason. I never done this in past, could you please let me know how do we perform this, is there any docs available?

Thanks

Converting a DG to a CG is quite straight forward. Actually the symdg command has a function that does it for you.

1. Take a copy of your DG with symdg export dg_name -file export_file_name.txt

2. Create a CG from an existing DG with command : symdg dg2cg dg_name cg_name

Now you are good to use the new composite group. If you want to add a second DG into the newly created CG use command : symcg -cg add dg dg_name

Note that if you want to maintain SRDF consistency between all devices in the CG (which contains devs frm both source arrays), The composite group must become a consistency group. It's just the same group with consistency enabled with command : symrdf -cg cg_name enable