duncanb@ibmpcug.co.uk (D G Booth) (06/27/90)
In article <940@metapyr.UUCPdavid@metapyr.UUCP (David Relson) writes: > In order to partition a disk so that both DOS & OS/2 can use it and boot from > it requires that you follow some special rules. > > The first rule is that DOS won't (can't) access a FAT partition that is on a > disk after a HPFS partition. Therefore for your needs all your FAT partitions > must be before the HPFS partition. > > Secondly the boot partition must be a FAT partition (for access by both > systems). > Neither of these are completely true. My hard disc is partitioned as follows: 1) 220Mb HPFS. Boot partition for OS/2 only. 2) 20Mb FAT. Boot partition for DOS only. 3) 79Mb FAT. Shared OS/2 DOS partition. Note that partition number 2 is DOS only - i.e. OS/2 does not see it. To get a disc like this install as follows: Backup your files. Delete any old partitions. Install OS/2. FDISK and FORMAT to give a 220Mb primary partition. Boot up DOS from a floppy. Use FDISK to create a 20Mb primary DOS partition, and the rest of the disc as a secondary DOS partition. FDISK at this point will see the OS/2 partition as an alien partition so it will leave it alone. Now if you use fdisk (or the pm equivalent) to change the active partition between 1 and 2, you will boot to OS/2 or DOS respectively. Shared files go on DRIVE D:, the third partition. Better than fdisk, there are programs around that will give you a menu on each reboot when you can select the partition to boot from (with a timeout default). Duncan Boothe -- In article <940@metapyr.UUCPdavid@metapyr.UUCP (David Relson) writes: In order to partition a disk so that both DOS & OS/2 can use it and boot from it requires that you follow some special rules. The first rule is that DOS won't (can't) access a FAT partition that is on a disk after a HPFS partition. Therefore for your needs all your FAT partitionsmust be before the HPFS partition. Secondly the boot partition must be a FAT partition (for access by both systems). Neither of these are completely true. My hard disc is partitioned as follows: 1) 220Mb HPFS. Boot partition for OS/2 only. 2) 20Mb FAT. Boot partition for DOS only. 3) 79Mb FAT. Shared OS/2 DOS partition. Note that partition number 2 is DOS only - i.e. OS/2 does not see it. To get a disc like this install as follows: Backup your files. Delete any old partitions. Install OS/2. FDISK and FORMAT to give a 220Mb primary partition. Boot up DOS from a floppy. Use FDISK to create a 20Mb primary DOS partition, and the rest of the disc as a secondary DOS partition. FDISK at this point will see the OS/2 partition as an alien partition so it will leave it alone. Now if you use fdisk (or the pm equivalent) to change the active partition between 1 and 2, you will boot to OS/2 or DOS respectively. Shared files go on DRIVE D:, the third partition. Better than fdisk, there are programs around that will give you a menu on each reboot when you can select the partition to boot from (with a timeout default). Duncan Booth -- -- Automatic Disclaimer: The views expressed above are those of the author alone and may not represent the views of the IBM PC User Group. --