Software Development Kit (SDK) and API Discussions
Sorry I didn't found any cDOT API of volume quota modify -state on/off.
Have anyone can provide it?
The quota-on, quota-off, and quota-resize APIs perform the operations of volume quota modify -state on/off/resize. Note that they are Vserver APIs, so you will need to connect to a Vserver or set the Vserver name in your code to use them.
Let me know if you need further help.