A magnetic robot includes a chassis and at least one track assembly associated with the chassis. Upon receiving a request to create a thick data volume having a requested number of the physical storage units, an available number of the physical storage units that are available in the thin provisioned pool can be identified. The card cage is insertable into the 2U rackmount chassis. The reagent comprises a haemolysing agent for lysing red blood cells in the blood sample, and optionally a staining agent for selectively staining thrombocytes in the blood sample. A were relief notch is positioned adjacent the sampling cavity.