SAS spec has one suggestion that you may need to disable the ARC-8026 self-discovery function on putting it after 3G ARC-8020. How to disable self-configuration function?
CLI> SCE off
We released SAS expander F/W to support SCE function since Nov 2011. Please make sure you have updated to new F/W.
Tags: ARC-8020, ARC-8026, daisy chain, firmware, SAS