Using a Y-cable is fine.
Originally Posted by Mad Wolf
So far I have not heard of any HDD enclosures being incompatible with PS2ESDL yet.
If you are unsure, just avoid those that have cheap skate enclosures (Especially those with no brands).
Multi-functional devices are not supported.
Please use a device that was designed to only function as a USB mass storage device and nothing else (In other words, use a USB HDD that only functions as a USB HDD).
SCPH-10000 S. MINOKAMO v1.01 (Defunct)
SCPH-10000 S. KISARAZU v1.00 (faulty)
SCPH-15000 S. KOHDA (With warranty seal!) :D
DESR-5100 S. EMCS