SFP power value close to lower limit on storage
Applies to
- FAS/AFF systems
- ONTAP 9
- Fiber Channel (FC)
Issue
- FC link break, link flapping and/or FCP performance degradation.
- Below error recieved regarding storage LIF on NetApp:
Service: Interface FCP XXX.FC_LIF State: CRITICAL Time: Wed Mar 15 15:16:13 CET 2023 Description: CRIT - State: online, 8 Gbit/s (wrong speed, expected 16 Gbit/s)(!!), Address x0:0a:09:84:80:74:xy:xx, Read: 1235654.27, Write: 9303298.57, Read OPS: 71, Write OPS: 138, Latency: 1.15 ms, Read Latency: 0.03 ms, Write Latency: 1.08ms
network fcp adapter showon ONTAP CLI displays low TX power:
Received Optical Power 570.7 (uWatts)
SPF Transmitted Optical Power 123.8 (uWatts)
- Low Rx power indicates an issue upstream to the storage port, i.e defective hardware incuding cable and sfp on switch end.
- Low Tx power indicates an issue on the storage port.
- The below values are approximate values:
|
SFP Version |
Light Value Ranges |
|---|---|
|
Shortwave 2/4/8gb SFP Receive Power Range Shortwave 2/4/8gb SFP Transmit Power Range |
-6 dBm (250 uWatt) to -2 dBm (630 uWatt) -6 dBm (250 uWatt) to 0 dBm (1000 uWatt) |
|
Shortwave 4/8/16gb SFP Receive Power Range Shortwave 4/8/16gb SFP Transmit Power Range |
-5.2 dBm (300 uWatt) to 0 dBm (1000 uWatt) -5.2 dBm (300 uWatt) to -1 dBm (790 uWatt) |
|
Shortwave 8/16/32gb SFP Receive Power Range Shortwave 8/16/32gb SFP Transmit Power Range |
-4.6 dBm (340 uWatt) to 2 dBm (1580 uWatt) -4.6 dBm (340 uWatt) to 2 dBm (1580 uWatt) |
- May occur in correlation:
- Increasing error counters on switch ports
- IO failures and/or timeouts on host OS
- One or more failed paths from host OS
- FC Target port on storage controller is in status <
OFFLINE> or <LINK NOT CONNECTED> - Link resets/port resets
- Adapter found hung errors