I have considered Azure Standard_E16s_V3 vm and attached two premium disks (p30 , 1024 GB & 5000 IOPS). How can I calculate the average IOPS considering both disks. This is to check the possible reason of slowness. Initially there was a single disk and performance was very slow and we attached another disk but the slowness is the same. What is the way to calculate the effective IOPS and what are the parameters to improve the slowness
There are several possibilities: 1) Use Azure Monitor. Scope -> Select the host Metric Namespace -> Virtual Machine Host Metric -> Data Disk Read/Write Operations Aggregation -> Avg This will give you 1 aggregated metric for all data disks, but now you can "Apply splitting" to get 1 line per LUN on the graph
2) You could use a Grafana dashboard to display the disk performance metrics. If you have the disk IOPS metrics in a monitoring solution such as Prometheus or Zabbix, creating a Grafana dashboard is easy and will allow you to correlate multiple metrics.
If one of your disks is reaching the IOPS or throughput limits, that could indeed explain slowness, but there are of course a lot of other possible reasons for slow performance.