"For much of the Middle Ages, single-volume Bibles must have been as rare as manuscripts of the separate parts of the Bible were common" (McGurk, "The Oldest Manuscripts of the Latin Bible" IN: Gameston, ed., The Early Medieval Bible. Its production, decoration and use  2).
The earliest surviving Latin single-volume Bible is the León palimpsest (Palimpsestus Legionensis) written in two columns in a crowded half-uncial. (Archivio Catedralicio 15, Lowe, Codices Latini Antiquiores XI, 1636). Of the original New Testament 40 leaves have survived in the palimpsest as the undertext. The overtext contains a 10th century copy of Rufinus's translation of Eusebius's Church History. Lowe states that this manuscript was presumably written in Spain because of the presence of "Visigothic symptoms." The Bible text was used for rewriting in a Spanish scriptorium in the ninth century. It is preserved in the Cathedral of León, León, Spain.
McGurk, op. cit., 7.