Messages in this thread | | | Date | Tue, 28 Aug 2001 14:23:15 +0200 | From | Guest section DW <> | Subject | Re: Determining maximum partition size on a hard disk |
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On Tue, Aug 21, 2001 at 03:55:55PM -0400, Nick DeClario wrote:
> I am trying to calculate the maximum size a partition can be on a hard > drive and I ran into some problems I don't fully understand. > > First I found that the maximum size of the drive Linux reports is not > the maximum size I get when I calculate it from the drives geometry. > Secondly, the total drive space reported by linux is not the amount > available for the maximum partition. > > For example, I have a 4.3Gb disk. The drives geometry is 525 cylinders, > 255 heads and 63 sectors (525 * 255 * 63 * 512 = 4318272000 or > 4.318Gb). > > This is an IDE disk so I found in /proc/ide/hdx/capacity a block size > 8439184, which when divided by 2048 is 4120.7, ~200Mb less than what I > calculated as the disk size.
I don't know why you would want to divide by 2048. Multiply by 512 and find 512*8439184 = 4320862208 bytes. Since that is more than you thought you had, be happy.
> I assume that the difference between the maximum size that linux reports > and the maximum partition size is due to linux leaving room for a MBR
No. There are rounding differences. The disk capacity is not an integral number of cylinders and you lose if you insist on alignment.
Find a lot of details in the Large Disk Howto.
> I thought maybe Linux set 1MB=1000k but that doesn't seem to case.
Well, 1 M = 1000 k by definition of the SI system of units. This has nothing to do with Linux. But if you are confused about units, just compute in bytes. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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