How to reduce workload driven disk utilization in ONTAP 9
Applies to
ONTAP 9
Issue
- Disk IO latency is appearing due to too many operations at the same time due to user workload.
- Multiple volumes from a particular SVM/aggregate report high latency.
- Using Active IQ Unified Manager or
qos statistics volume latency show
, latency is shown to be in the Disk or Aggregate Processing (Active IQ Unified Manager), and latency is actively impacted on the target volume.
Example:
cluster1::> qos statistics volume latency show -vserver svm1 -volume vol1 Workload ID Latency Network Cluster Data Disk QoS Max QoS Min NVRAM --------------- ------ ---------- ---------- ---------- ---------- ---------- ---------- ---------- ---------- -total- - 4.71ms 185.00us 7.00us 468.00us 4.04ms 0ms 0ms 11.00us vol1 32140 22.22ms 86.00us 125.00us 904.00us 21.11ms 0ms 0ms 1.00us -total- - 4.58ms 253.00us 7.00us 991.00us 3.32ms 0ms 0ms 11.00us vol1 32140 29.69ms 90.00us 162.00us 2.61ms 26.82ms 0ms 0ms 1.00us -total- - 2.55ms 229.00us 8.00us 589.00us 1.71ms 0ms 0ms 13.00us vol1 32140 18.84ms 61.00us 314.00us 136.00us 18.32ms 0ms 0ms 1.00us -total- - 4.33ms 198.00us 9.00us 1221.00us 2.88ms 0ms 0ms 13.00us vol1 32140 177.16ms 113.00us 226.00us 108.03ms 68.79ms 0ms 0ms 2.00us
- The qos command
qos statistics workload resource disk
show listUser-Default
as the top DISK workload.
Example:
cluster1::> qos statistics workload resource disk show -node nodeB Workload ID Disk Number of HDD Disks --------------- ------ ----- ------------------- -total- - 98% 44 User-Default - 83% 44 _Efficiency_... - 10% 44 _WAFL - 3% 44 _RAID - 2% 44