QoS Limits causing high volume latency
Applies to
- ONTAP 9
- AFF Series
- FAS Systems
- CVO
- Quality of Service (QoS)
Issue
-
QoS is used to help regulate workloads competing for finite Cluster CPU and Disk resources
- Elevated LUN /volume/Qtree latency observed once QoS limits are reached
- As workloads change, QoS limits may need to be adjusted to help manage client performance expectations.
- May see this alert: AIQUM Event alert, Workload LUN latency threshold breached defined by Performance Service Level Policy
- Audit logs shows the
- Delay center QoS Max will show high latency from CLI
cluster::> qos statistics volume latency show -volume qostest -vserver testsvm Workload ID Latency Network Cluster Data Disk QoS Max QoS Min NVRAM --------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- -total- - 646.73ms 1377.00us 0ms 262.00us 9.49ms 635.60ms 0ms 0ms qostest-wid23.. 23350 646.73ms 1377.00us 0ms 262.00us 9.49ms 635.60ms 0ms 0ms -total- - 634.31ms 1430.00us 0ms 263.00us 6.78ms 625.83ms 0ms 0ms qostest-wid23.. 23350 634.31ms 1430.00us 0ms 263.00us 6.78ms 625.83ms 0ms 0ms -total- - 640.86ms 1324.00us 0ms 304.00us 7.62ms 631.61ms 0ms 0ms qostest-wid23.. 23350 640.86ms 1324.00us 0ms 304.00us 7.62ms 631.61ms 0ms 0ms -total- - 659.83ms 1357.00us 0ms 303.00us 7.50ms 650.67ms 0ms 0ms qostest-wid23.. 23350 659.83ms 1357.00us 0ms 303.00us 7.50ms 650.67ms 0ms 0ms