i make little progress , so report it . I install openbsd first in HDD. then I install puppy linux .
1) use puppy' fdisk ,then # fdisk /dev/sda Device Boot Start End Blocks Id System /dev/sda1 * 2048 10487807 5242880 83 Linux <-puppy /dev/sda2 10487808 55830527 22671360 83 Linux <-ext2 /dev/sda3 55830528 78140159 11154816 a6 OpenBSD i will want to use this ext2 from puppy and openbsd . 2)puppy's grub4dos controls ' boot proess openbsd or puppy ' menu.lst in sda1 is next. title OpenBSD chainloader (hd0,2)+1 rootnoverify (hd0,2) boot 3)in openbsd disklabel wd0 is next # size offset fstype [fsize bsize cpg] a: 19426368 56886176 4.2BSD 2048 16384 1 # / b: 1055637 55830528 swap # none c: 78140160 0 unused namely , ext2 is not shown . because i make ext2 after i install openbsd . therefore i must 'disklabel -e' details is next. good Material is in openbsd's 'fdisk wd0' #fdisk wd0 Disk: wd0 geometry: 4864/255/63 [78140160 Sectors] Offset: 0 Signature: 0xAA55 Starting Ending LBA Info: #: id C H S - C H S [ start: size ] ------------------------------------------------------------------------------- *0: 83 0 32 33 - 652 213 9 [ 2048: 10485760 # # # ] # # Linux files* 1: 83 652 213 10 - 3475 73 54 [ 10487808: 45342720 # ] Linux files* 2: A6 3475 73 55 - 4863 254 63 [ 55830528: 22309632 # ] OpenBSD 3: 00 0 0 0 - 0 0 0 [ 0: 0 ] unused # # # # i remember 10487808 & 45342720 then command disklabel -e wd0 and then vi editor come up . following openbsd FAQ , i add 'o: line' . see below # size offset fstype [fsize bsize cpg] a: 19426368 56886176 4.2BSD 2048 16384 1 # / b: 1055637 55830528 swap # none c: 78140160 0 unused o: 45342720 10487808 ext2fs and at last mount_ext2fs /dev/wd0o /EXT2 but this same method 'disklabel -e' donot go well in USB memory . so i boot openbsd and puppy on USB by openbsd's grub . see http://openbsd-akita.blogspot.jp/2014/06/openbsad-runs-on-usb-memory-no-need-hdd.html mis ----- tuyosi