Hi ben78,

I would suggest that you take a look at the Dynamic Pool White Paper:

https://support.emc.com/docu85573_Dell_EMC_Unity:_Dynamic_Pools_-_Overview.pdf?language=en_US

The Raid Width is determined automatically at initial creation (via GUI) based on the number of drives and is not changed afterwards when more drives are added (see pages 15-16 of the above doc).

If you have a particular width in mind, you have to provide the required number of drives at initial creation via GUI for this to take place.

You may be able to manipulate this with UEMCLI / RestAPI

Once you create your pools, you can check the Raid Width (or Stripe Length) with:

uemcli -no /stor/config/pool show -detail (or -filter as shown below)

Example here showing pool test1 created initially with 6 drives and then expanded to 15, and test2 initially created with 10 drives:

uemcli -no /stor/config/pool show -filter "Name,RAID level,Stripe length,Number of drives"

1:    Name             = test1

      RAID level       = 5

      Stripe length    = 5

      Number of drives = 15

2:    Name             = test2

      RAID level       = 5

      Stripe length    = 9

      Number of drives = 10

Andre @ Dell EMC

Since you are an EMC employee you can also look at the trainings available internally plus the stuff on Yebo