Saturated network switch port can cause latency when copying via NAS protocols
Applies to
- ONTAP 9
- AFF and FAS platforms
- NAS Protocols
- NFS
- CIFS
- Network Switches
- Cisco
- Broadcom
- Others, as applicable in environment
Issue
- Slow file copy/transfer and/or files not copying.
- Storage performance evaluation does not indicate high latency or resource bottlenecks (such as Disk or CPU)
- Discards or other errors may be observed in ifstat output
- Packet traces from storage and client show:
- High Round Trip Time (RTT) values
- How to identify if packet drops are seen
- Dropped Receive packets
- DUP ACKs
- Out-of-order packets
- fast_retransmission and retransmission packets