High volume latency and applications are stopping
Applies to
- ONTAP
- SAN
- FCP
Issue
- High volume latency (over 110 ms ) and applications are stopping:
::*> qos statistics volume latency show
Workload ID Latency Network Cluster Data Disk QoS NVRAM Cloud FlexCache SM Sync
--------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
-total- - 55.36ms 45.75ms 6.00us 926.00us 8.67ms 0ms 5.00us 0ms 0ms 0ms
my_lun_.. 25247 125.04ms 124.59ms 1.00us 279.00us 170.00us 0ms 0ms 0ms 0ms 0ms
my_lun__.. 23052 108.73ms 108.19ms 5.00us 218.00us 318.00us 0ms 0ms 0ms 0ms 0ms
- EMS shows the following errors from one particular device 40A00:
Tue Mar 08 01:02:01 +0100 [NETAPP: fct_tpd_work_thread_0: fcp.io.status:debug]: STIO Adapter:1b IO WQE failure, Handle 0x1, Type 8, S_ID: 40A00, VPI: 275, OX_ID: 6E8, Status 0x3 Ext_Status 0x1d
Tue Mar 08 01:03:21 +0100 [NETAPP: fct_tpd_work_thread_0: fcp.io.status:debug]: STIO Adapter:1b IO WQE failure, Handle 0x1, Type 8, S_ID: 40A00, VPI: 275, OX_ID: 543, Status 0x3 Ext_Status 0x1d sfpshowon the switch port where a device with the errors is connected shows a very low received optical power(RX) signal:
switch# switchshow
Index Slot Port Address Media Speed State Proto
============================================================
14 1 14 040a00 id N8 Online FC F-Port 51:40:2e:c0:xx:xx:xx:xx
switch# sfpshow 1/14
=============
Slot 1/Port 14:
=============
RX Power: -26.0 dBm (2.5 uW)
TX Power: -3.3 dBm (467.5 uW)