How to change Disk Partition types

Question

How to change Disk Partition types

I posted this a while ago, but got no respones so let me try again.

I have two drives, both with multiple partitions. On my boot drive, I have an Apple_UFS partition that's empty. I now want to be able to use if for Mac data files - pdfs, word docs, etc. (I'm running 10.4.11 on a powerpc - when I can afford an Intel macbook, I'll upgrade to Leopard).

Questions:

1) Will puttting Mac files on a Apple_UFS volume cause problems (rsource & data forks, meta data in files)? (If its OK, then skip to Q6 which I'd like to know for future reference).

2) Should I change the partition type (to Apple_HFSX)? There's no data on it now, so that's not a problem.

3) Disk Utility won't let me change partition type, only change the name. Diskutil has the command " eraseVolume format name device", but I suspect that format is the current format, not a new format - please correct me if I'm wrong.

4) pdisk interactive mode has the "t" command which looks like what I want.

5) after the partition type is changed, I presume I then need to use newfs_hfs -

6) I am confused about the device/partition name - "diskutil -l" shows "/dev/disk0" with the partition I want to change as "disk0s11". "pdisk - l" shows "/dev/rdisk0" and the partition number as 11. The "newfs_hfs -h" gives an example of "newfs_hfs -v Untitled /dev/rdisk0s7".

So in my case, is my device "/dev/rdisk0s11"??

Thanks for any help on this confusing matter.

Mini - 1.42, Mac OS X (10.4.9), 1Gig (self installed)

Posted on Apr 16, 2009 9:34 AM

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Answer 1

Camelot

Level 9

59,085 points

Apr 17, 2009 11:20 AM in response to frankinmelrose

1) Will puttting Mac files on a Apple_UFS volume cause problems (rsource & data forks, meta data in files)? (If its OK, then skip to Q6 which I'd like to know for future reference).

It won't be a problem to use UFS. However, bear in mind that Leopard dropped support for formatting UFS volumes in Disk Utility.app. While you can still use them it might indicate that it's not your best long-term option.

2) Should I change the partition type (to Apple_HFSX)? There's no data on it now, so that's not a problem.

Can't hurt, and this is the preferred format for Mac-specific drives.

3) Disk Utility won't let me change partition type, only change the name. Diskutil has the command " eraseVolume format name device", but I suspect that format is the current format, not a new format - please correct me if I'm wrong.

EraseVolume is the option you want. the format parameter is the format you want the partition to use, not the current partition format (the current format is irrelevant if you're going to erase the volume anyway).

4) pdisk interactive mode has the "t" command which looks like what I want.

Never used pdisk. I don't see the need given the other tools available.

5) after the partition type is changed, I presume I then need to use newfs_hfs -

Not if you use i>diskutil eraseVolume. This will take care of everything.

6) I am confused about the device/partition name - "diskutil -l" shows "/dev/disk0" with the partition I want to change as "disk0s11". "pdisk - l" shows "/dev/rdisk0" and the partition number as 11. The "newfs_hfs -h" gives an example of "newfs_hfs -v Untitled /dev/rdisk0s7".

Again, IMHO ignore pdisk.

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Answer 2

Apr 17, 2009 1:47 PM in response to Camelot

Thanks for excellent and detailed answer. I'm not going to be able to do this till Sunday, so I'm going to hold the thread open just in case I have any more questions.

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