A minimum of two personnel "are" or "is"?
Your question relates to a common ‘singular versus plural’ dilemma, where there is a reasonable case for each.
1 A minimum of two personnel are required to ....
It is tempting to say that the plural “two personnel” is embedded in the singular “a minimum” and so the copula should be plural.
- A minimum of two personnel is required...
“A minimum” (singular) is the grammatical subject of the copula and so the copula should be singular (is).
Think of other ways of saying this.
what is required ... is a minimum of two personnel.
The standard answer to such dilemmas is to say it depends whether the writer is thinking of the singular unit or the plural members of it. But the decision to plump for one or the other is ultimately arbitrary. To some one feels wrong, to others the other does. So I have chosen to say it doesn’t matter.
Except either of the alternatives will bother somebody. So a principle (which I admit has no support in grammatical law) of ‘being considerate to the audience’ should apply: rephrase it entirely. And one is ready to hand (and briefer too):-
At least two people are required ....
"A minimum of two personnel are required to meet this objective" is correct, even though the word "minimum" may be read as singular.
For an explanation regarding a similar question, please read @Jimi Oke's excellent answer here.