Increased latency due to high QOS minimum latency after upgrade to ONTAP 9.7
Applies to
- ONTAP 9.7 or ONTAP 9.8
- Quality of Service (QoS)
- Adaptive Quality of Service (AQoS).
Issue
- The following EMS error may be observed:
[<node_name>: qos_vd_window_manager: qos.VioDet.maxThrottle:notice]: QoS violation limit for NODE <UUID> is 95424 IOPS.
- Increased latency due to QoS after upgrade to ONTAP 9.7
- High latency is visible in the
QoS Min
delay center, with low workloads
Example:
Cluster::> qos statistics volume latency show
Workload ID Latency Network Cluster Data Disk QoS Max QoS Min NVRAM
--------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
...
vol1-wid123 1456 719.23ms 383.00us 4.00us 525.00us 145.00us 0ms 717.99ms 177.00us
vol2-wid234 16744 716.25ms 386.00us 4.00us 613.00us 117.00us 0ms 714.91ms 215.00us
vol3-wid567 6399 712.09ms 442.00us 0ms 1281.00us 1284.00us 0ms 709.08ms 0ms
- VMware alarms report lost access to the affected volumes for a few seconds
Lost access to volume xyz due to connectivity issues. Recovery attempt is in progress and outcome will be reported shortly.