Open the ISO in UltraISO . Look for files named DUMMY.DAT , PADDING.BIN , or files larger than 1GB. Delete these (they are placeholders).
The original Black PS2 HDD adapter supports drives up to 2TB (with homebrew). A single game like God of War II takes up 8GB. Without compression, a 2TB drive holds ~250 games. With ISOs, you can fit over 1,500 games on the same drive. black ps2 highly compressed