There aren't many clean options for this. You could regulate access to the /etc/quotas file via permissions so they could edit it, then create a user on the controller that only has access to the quota command using the RBAC funtionality.
A cleaner, but more complicated way would be to write a program/script that uses the
that does exactly what you want. I'm not aware of one that's already written though so you'd have to be comfortable writing code to go this route (thus it's potentially more complicated).
I'm not sure if Operations Manager can use RBAC to that granular level, but if it could, that would be an option. I'll let others comment on that if they know.
