NetApp HCI Manual page 27

sustained.
QoS value limits
Here are the possible minimum and maximum values for QoS.
Parameters Min value
Min IOPS 50
Max IOPS 100
Burst IOPS 100
*These estimations are approximate.
**Max IOPS and Burst IOPS can be set as high as 200,000; however, this setting is allowed only to effectively
uncap the performance of a volume. Real-world maximum performance of a volume is limited by cluster usage
and per-node performance.
QoS performance
The QoS performance curve shows the relationship between block size and the percentage of IOPS.
Block size and bandwidth have a direct impact on the number of IOPS that an application can obtain. Element
software takes into account the block sizes it receives by normalizing block sizes to 4k. Based on workload, the
system might increase block sizes. As block sizes increase, the system increases bandwidth to a level
necessary to process the larger block sizes. As bandwidth increases the number of IOPS the system is able to
attain decreases.
The QoS performance curve shows the relationship between increasing block sizes and the decreasing
percentage of IOPS:
Default 4 4KB
50 15,000
15,000 200,000**
15,000 200,000**
5 8KB 6 16KB
9,375* 5556*
125,000 74,074
125,000 74.074
262KB
385*
5128
5128