Anarcho-primitivists share many characteristics with survivalists, most notably predictions of a pending ecological disaster. Writers such as Derrick Jensen argue that industrial civilization is not sustainable, and will therefore inevitably bring about its own collapse. Non-anarchist writers such as Daniel Quinn, Joseph Tainter, and Richard Manning also hold this view. Some members of the Men Going Their Own Way subculture also promote off-grid living and believe that modern society is no longer liveable.
Common preparations include the creation of a clandestine or defensible retreat, haven, or bug out location (BOL) in addition to the stockpiling of non-perishable food, water, water-purification equipment, clothing, seed, firewood, defensive or hunting weapons, ammunition, agricultural equipment, and medical supplies. Some survivalists do not make such extensive preparations, and simply incorporate a "Be Prepared" outlook into their everyday life.
To me, the best option is to store emergency food. How much? If you have none, store enough for a few days. If you have enough for a few days, get enough for a week. How much you store depends on what time frame you think you're at risk for having to be completely independent. The early settlers of the southwest liked to store enough food for a whole year and still do to this day!