Poor reading performance due to COS4 Last updated Save as PDF Share Share Tweet Share Views:116Visibility:PublicVotes:0Category:ontap-9Specialty:PerfLast Updated: Applies to ONTAP 9 Quality of service (QOS) Class of service (COS) Cisco Nexus 9K switch Issue Very poor network performance regardless of protocol used Outgoing netapp traffic is marked with CoS bit 4