It may take a unanimous action of the members of a limited liability company to dissolve the entity or to change the date on which the company will dissolve according to the terms of its operating agreement. But unless the Operating Agreement specifically requires the members to act unanimous to extend the company, a simple majority may suffice.
That was the holding of the New Hampshire Supreme Court in McDonough v. McDonough, a case in which one of the members of this family business attempted to enforce a dissolution provision in the operating agreement to force the purchase of his shares.