How to delete a partition

Question

Level 1

8 points

How to delete a partition

I have an external 250GB drive with 4 paritions. They were all NTFS. I have moved files around and converted the first 3 partitions to Mac OSX Extended. I want to now delete partitions 2 and 3, and then create one new Mac OSX Extended partition there. When I tell Leopard to delete the partition, it refuses and throws a cryptic error:

MediaKit reports partition (map) too small.

I have searched the internet for a resolution to this with no luck. Any help?

Details - Current State:

Partition 1 - Mac OSX Extended (41.0 GB / 11.8 free)
Partition 2 - Mac OSX Extended (41.0 GB / 41.0 free)
Partition 3 - Mac OSX Extended (51.0 GB / 51.0 free)
Partition 4 - NTFS (99.6 GB / 12.2 free)

Future State:

Partition 1 - Mac OSX Extended (41.0 GB / 11.8 free)
Partition 2/3 - Mac OSX Extended (92.0 GB / 92.0 free)
Partition 4 - NTFS (99.6 GB / 12.2 free)

Alternate Future State (also acceptable):

Partition 1/2/3 - Mac OSX Extended (133.0 GB / 133.0 free)
Partition 4 - NTFS (99.6 GB / 12.2 free)

I can't believe what I'm trying to do would not be supported. And I'm not sure what the media kit is. And I'm not sure why a partition map would be too small. But then I'm new to Mac.

MacBook Pro 17, Mac OS X (10.5.7)

Posted on Jul 12, 2009 7:21 AM

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Answer 1

KJK555

Level 4

2,900 points

Jul 12, 2009 1:08 PM in response to clairdemoon

I don't know how your partition map is laid out, but most likely you have an msdos partition that
has been subdivided into one or more dos logical partitions. You are probably trying to combine
an HFS+ APM (Apple Partition Map) volume with a Subdivided msdos type partition, and that is why
you are receiving that error message.

Technically, if that is the case, your only option is (without destroying and recreating the entire
partition map structure) is to delete the correct msdos subdivided partition, shrink the msdos
partition to reclaim the free space, add the free space to your HFS+ APM partition.

Now for the really bad news; that generally requires moving (a) partition(s) and all asscociated data,
and that is something that Disk Utility simply cannot do.

Which leaves you with two choices, repartitioning your drive from scratch, or purchasing a
partitioning software that can accomplish such a feat, such as iPartition.
http://www.coriolis-systems.com/iPartition.php

Whatever you do, back up your data first, if you want to keep it because Partitioning under the best
of conditions is still a gamble, with an unacceptable risk of failure that will result in loss of data.

Kj

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Answer 2

clairdemoon Author

Level 1

8 points

Jul 17, 2009 9:36 AM in response to KJK555

Or just use Windows XP. Which I did. It took 5 minutes. I deleted the partitions I didn't want, merged the empty space, created a new partition in it, formatted it with FAT32, and then brought them back over to OSX. After that OSX could reformat the partitions with Mac OS Extended.

Final State (as desired):

Partition 1 - Mac OSX Extended (41.0 GB / 11.8 free)
Partition 2/3 - Mac OSX Extended (92.0 GB / 92.0 free)
Partition 4 - NTFS (99.6 GB / 12.2 free)

Thanks for the response, KJK555. The information you gave me was definitive and consistent with everything else I could find (and not find) about partitioning on Mac OS X.

BOTTOM LINE: Keep a copy of Windows around for disk partitioning when multiple file systems are required. Windows had no problem working with the partitions it could read while displaying the others as unknown file systems. In this case, Windows was better than Unix.

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Answer 3

R C-R

Level 6

17,782 points

Jul 17, 2009 10:49 AM in response to clairdemoon

In this case, Windows was better than Unix.

FWIW, NTFS is actually not an open file system standard but a proprietary one owned & controlled by Microsoft. Unless you are manipulating it under Windows, you are relying on reverse engineered, third party solutions to do so. Because this could potentially lead to data loss if MS makes some change to the private part of the NTFS specifications or features, Apple chose to include read only support for it in OS X. OS X fully supports Fat32, mostly because it is old & stable, & the lowest-common-denominator file system in use in the industry.

BTW, the Apple Partition Map (APM) partition scheme does not support NTFS partitions, so your external drive must have been formatted with another scheme, probably GUID Partition Table (GPT).

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Answer 4

clairdemoon Author

Level 1

8 points

Jul 23, 2009 9:18 AM in response to R C-R

Sorry, but you don't know what you're talkng about, R C-R. Maybe you need to read the thread again. And if you do, you'll probably realize that that no reverse engineered or third party solutions were used by me.

So. Nobody needs to be scared and run down the street screaming like little girls.

The bottom line is:

WINDOWS IS BETTER AT MANAGING PARTITIONS THAN MAC OS X.

If you have a disk with any combination of Fat, NTFS, HFS, or other partitions, the Disk Management Utility that comes with Windows can delete the partitions, merge the empty space, and optionally reformat the new partition to on of its supported formats (FAT32, NTFS) without affecting the other partitions, whether they are supported or not. However, the Mac Disk Utility cannot do this. It can only repartition the disk if ALL of the partitions are Mac OS X supported (FAT32, HFS).

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Answer 5

Jul 23, 2009 10:03 AM in response to clairdemoon

I think you are the one who is failing to read the post. R C-R is not saying that you did the reverse engineering but those whose code you have installed did it.

I have some real problems with your accretion that Winders can handle partitions better then Mac OS X. Personally with all my years in IT support I question whether Microsloth is able to do anything well but that is another story.

Allan

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Answer 6

KJK555

Level 4

2,900 points

Jul 23, 2009 10:45 AM in response to clairdemoon

Hi clairdemoon:
Your right about Windows being able to manage the MBR partition, be sure to use xp service pack2
(minimum) or later version of windows because earlier versions are not GPT (GUID) aware.

Very few (if any) third party windows disk utilities are GPT aware and will destroy your MBR partition.

iPartition, the Mac disk utility partitioning program allows you to hide or allow windows to see
Mac partitions. Some versions of Linux disk utilities work well with Mac GPT volumes.

Kj

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