[fdisk] Creating a partition at the outer edge of hard drive

Somewhere · n00b Joined: 01 Jul 2008 Posts: 38

I know this may be an unusual desire, but I want to know how it can be done none the less.

The Gentoo installer lets me use # fdisk to manipulate my partition schema. How can I use this tool to create an partition at the outer edge of my disk? I am asked to define the first and last cylinder of my partition. I am, however, not sure how to calculate how many cylinders would make up the partitions I desire.

I want /boot to be a 75 MB partition at the outer edge of my hard drive. I also want a 2 GB swap partition to be placed just next to the boot partition. The others partitions I can manage with this tool myself. But the two I want on the outer edge, I do not know how to specify.

The hard drive is a 100 GB disk with cylinders 1–12161, if it helps. :idea:

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

If you were to use cfdisk instead of fdisk, it lets you specify if you want to have the partition at the beginning, or at the end of the drive, and you can work with (approximated) size in megabytes instead of sectors/cylinders.

What exactly do you mean by outer edge though? For hard disks, it should usually be the first sector that is outside (i.e. in the fastest region of the drive) and the last sector inside (slowest region).

Especially /boot is something you usually put at the start of the drive because boot loaders sometimes can't see the end of it.

Somewhere · n00b Joined: 01 Jul 2008 Posts: 38

I have always thought you ought to put it at the end of the hard drive, and that the end (last cyliders) were the outer edge of the hard drive.

Does not a hard drive start at the center of the disk (sector 1) and end at the outer edges of the disk (sector 12161)? It may very well be that I have misunderstood and that it works in reverese.

frostschutz · Advocate Joined: 22 Feb 2005 Posts: 2977 Location: Germany

No... optical media like CD/DVD-R write from inside to outside (maybe it's easier to put into hardware this way or the outside is avoided since that is where you touch the media and where the chance for media damage is greatest), but for hard disks it's the other way around, they write from outside to inside usually, because system and files tend to go into the first sectors (they are even moved there by defraggers), so it should be the fastest area.