symqos to throttle SRDF Adaptive copy

I am running SRDF/Metro setup using one pair of VMAX 250 FX.  Due to DC relocation,  I need to host a 3rd copy as we need to relocate the R2 box to a new location.   During the relocation, we will need to maintain SRDF/A copy to protect the production data.


Before we have introduced the SRDF/Adaptive copy, the RDF % busy already hit 70% or 80% all the time.   Now with the new SRDF/Adaptive copy introduce, it impact the performance as the RDF % busy is going up to 100%.  This impact the host response time.  


I am going to implement symqos.  There are two ways to set the QOS; first throttle by percentage, second throttle by pace


If I throttle by percentage, I am worried that the SRDF/Metro traffic already can hit 70% it might not give me the flexibility here since I can potentially limit my SRDF/metro utilization.

symqos -RA -sid 1234 enable -io

symqos -RA -sid 1234 set IO -default -sync 60 -async 30 -copy 10


The second is to use symqos and set pace from device level.

symqos -sid 1234 set RDF pace 8 -devs AAA:BBB,EEE


The second option seem more appealing to me but I am not sure whether the pace setting will impact the SRDF/Metro copy as well.