Problem scenario
You run quota -g foobar where "foobar" is the name of the group you want a quota to apply to. But you get this: "Disk quotas for group foobar: no limited resources used"
What should you do?
Possible solution
Run a command like this:sudo quotacheck -gm /path/to/filesystem
(Don't use the -u flag if you have no user quota configured.)
Now try the quota -g foobar command again.