Custom IOPS not applied to root disk when deploying a VM from a template

Start at CloudOrchestrator.createVirtualMachine() and trace how vm_instance_details values are read into DiskOfferingInfo. Compare the minIops/maxIops detail names with the API constants MIN_IOPS and MAX_IOPS, then verify that the ROOT volume receives both values during deployment. Confirm the fix with the linked pull request and a deployment test using custom IOPS.

problem

Description

When a user deploys a VM from a template with a Custom IOPS offering for the ROOT disk, the min IOPS and max IOPS entered in Deploy Instance are stored in VM details but not copied to the ROOT volume.
volumes.min_iops and volumes.max_iops stay empty. Vendor storage that reads IOPS from the volumes gets null for min IOPS and max IOPS instead of the values entered at deploy.

Root Cause

The UI sends custom IOPS as details[0].minIops and details[0].maxIops. CloudStack stores them in vm_instance_details with those same names (minIops / maxIops).

When the ROOT volume is created, CloudOrchestrator.createVirtualMachine() reads IOPS using the API constants MIN_IOPS and MAX_IOPS. Those constants are miniops and maxiops.

The names do not match, so the lookup finds nothing. DiskOfferingInfo is left with no IOPS, and VolumeOrchestrator creates the ROOT volume with empty min_iops / max_iops.

It is a regression from Apache CloudStack PR: https://github.com/apache/cloudstack/pull/8800 (April 2024).

Observations:

vm_instance_details has minIops / maxIops

ROOT volume min_iops / max_iops are NULL

versions

CloudStack: 4.20 and later, including 4.23.

The steps to reproduce the bug

1. Go to Instances → Add Instance.
2. Select a template (do not use ISO).
3. In Compute offering, set Override root disk offering to true and select the Custom IOPS disk offering for the ROOT disk.
4. Enter min IOPS and max IOPS (for example, 100 and 1000).
5. Complete the wizard and deploy the VM.
6. After the VM is created, check the ROOT volume and VM details

What to do about it?

Impact

• The VM deploys with no error even though min and max IOPS are not applied on the ROOT volume.
• Expected IOPS are not served because custom min/max IOPS are not set on the ROOT volume, so there is no IOPS guarantee.

Expected Behaviour

Custom IOPS from deploy-VM details must be applied to the root volume