64- and 48-bit LBAs   SCSI primer: commands called CDBs CDBs come in different sizes 6-byte: 21-bit LBA; 10–12 32-bit; 16–32 64-bit “READ CAPACITY (12)” is a 12-byte command Background: most sd drivers use sdscsi which translates device discovery “online”: READ CAPACITY (10) CDB io “bio”: READ / WRITE (12) Command transation: prev next