What does NetBSD bootblock not on primary AHDI partition mean?
An explanation from Udo Erdelhoff: As you might know; every hard disk has a “root sector” that contains information about the size of the hard disk and the partitions on the hard disk. The root sector can only contain the necessary data for four partitions. Nobody thought that this limitation would cause any problems. After all, 640 KByte should be enough. As hard disks grew, it was necessary to define more than four partitions. In order to be more or less compatible with the old format, a new type of partition entry was defined: XGM partitions. An XGM partition is a “look over there” sign: Another root sector can be found at the start of the XGM partition. This root sector contains the remaining real partitions. And this is the big mystery: Partitions defined in the root sector of the hard disk are called “primary partitions”, partitions defined in the root sector of an XGM partition are called “extended partitions”. The bootblock will only work if the first NBD partition is a primary